Glossary of Terms

Throughout these guides and articles you'll be presented with many terms. Here are some of them that will be referenced often.

802.11: The family of specifications that have been determined for use in wireless networking. This includes the following specifications:

Adware: Adware can mean a couple of things. The most common is a form of spyware that collects data regarding your web browsing patterns and uses that data to target you with particular ads, generally in the form of pop-up advertisements. Adware can also be used to describe any program is installed on a computer that already has advertisements within the application. Not to be confused with Ad-Aware, which is a program created by Lavasoft that removes adware from a computer system.

AT: Standing for Advanced Technology, AT is a motherboard form factor introduced by IBM in 1985 and adopted by the PC industry (which wasn't much of an industry at the time, outside of IBM). AT boards measure 12"x12". It and Baby AT form factors are most easily recognizable by their keyboard ports, which are larger than ATX (about the size of a nickel).

ATX: The current standard for motherboard and case form factors, created by Intel in 1995. ATX was a graduation from the older AT form factor that was introduced in the IBM PC in 1984. Measures 12"x9.6". Uses PS/2 ports for both keyboard and mouse ports.

Baby AT: Successor to the AT form factor, and the most commonly used form factor until about 1997.

Bandwidth: The amount of data that can be transferred in a fixed amount of time. Measured in either bits per second (bps), bytes per second (Bps), or hertz (Hz).

Benchmark: A test designed to measure the performance of a particular piece of hardware. Websites, magazines, and other publications whose task it is to provide hardware reviews will use benchmarks to compare different products, so you as the consumer can make an informed choice. They will typically offer several benchmarks rating the device's performance in several categories, so that one or more of the results would be relevant to you (how many frames-per-second the newest 3D game runs won't make a difference to you if you're using the card for office applications).

BIOS: Basic Input Output System. Controls the features of the motherboard such as boot sequence, memory settings, and integrated peripherals. Built onto the CMOS on a motherboard.

Bit: A single piece of data, either a 0 or a 1. Designated by a lower-case B when dealing with abbreviations (Kb, Mb, etc.).

Boot: A term I guess I take for granted as I had two people today that didn't know what this meant, and I had to really think about how to describe it. The technical definition of "booting" is what the computer does after the POST (power-on self test). When a computer turns on and you see the memory test happening and the screen is black with white letters on it, that's the POST. When you see "Starting Windows" that's the boot.

Boot sequence: The boot sequence, defined in your BIOS, determines what order the computer looks for bootable devices on startup. For example, if your boot sequence is CD-ROM, floppy, primary hard disk, then after POST the computer will look for a bootable CD in your CD-ROM drive. If it finds one, it boots off of it, or prompts you to boot from it depending on the CD. If it does not find one, it will look at the floppy drive (this is when, after forgetting to pull your floppy out of the drive before rebooting, you would get a "Non-system disk or disk error" error when you try to restart). If it does not find a bootable floppy disk then it looks for your hard disk, where--hopefully!--it finds Windows and starts the boot process.

BPS: short for bits per second when spelled with a lower-case B (bps) or bytes per second when spelled with an upper-case B (Bps). This is VERY IMPORTANT when dealing with bandwidth, especially on the internet. I can't tell you how many times I've had a customer complain about their internet speed saying they're paying for 2Mbps (2 megabits per second) and are only getting 200KBps transfer speeds (200 kilobytes per second, which would be 2000 kilobits per second, which is 2 megabits per second!).

Broadcast: The act of simultaneously sending the same message to multiple recipients. In networking specifically, a data packet that is sent to all recipients on the network. Too many broadcasts can result in an overload on a non-switched network, called collisions.

Burner: Common name used for a CD-R, CD-RW, DVD-R or DVD-RW drive that actually writes or rewrites data to a blank disc (CD burner, DVD burner).

Bus: A data pathway connecting two or more devices. Measured by their speed (in megahertz) and their bandwidth (in bits).

Byte: A group of 8 bits. Designated by a upper-case B in abbreviations (KB, MB, etc.).

CAB files: CAB is short for cabinet. Microsoft generally uses cabinet files as compressed archives of installation files.

Case: The case is the physical housing that you put your computer parts into. Often inaccurately referred to as "the CPU" or "the hard drive".

CD-ROM: A CD-ROM is a data storage device. ROM stands for Read-Only Memory, meaning that data cannot be written to it, only read from it. Standard CD-ROMs store either 650 megabytes or 700 megabytes of data. This term can be used for either the media or for the drive itself.

CD-R: CD-Recordable. CD-R media can be written to, but only once. CD-R media can be read in most CD-ROM drives and audio CD players. This term can be used for either the media or for the drive itself (also called a burner).

CD-RW: CD-ReWritable. Like CD-R media, however CD-RW media can be erased and used again. However, CD-RW media is not compatible with all CD players. CD-RW drives can use both CD-R and CD-RW media, as well as play all CD-ROM media. This term can be used for either the media or for the drive itself (also called a burner).

Chip: A device consisting of several transistors (often many of them) that work together to form a complex task.

Chipset: A group of chips working together to perform certain functions, or provide support for functions.

CLI: Command Line Interface. Prior to the introduction of Apple computers and Windows, the only way to operate a computer. The operating system contains a complex list of commands that are entered from the command prompt. Seldom used in these days of the GUI except by the tech-savvy and for troubleshooting purposes. Some of the more complex (and dangerous) commands in Windows can only be run from the CLI in order to protect users from doing irreparable harm to their computers.

CMOS: Complimentary Metal Oxide Semiconductor. A semiconductor on the motherboard that stores the BIOS. Generally consists of a programmable "flash" memory so the BIOS can be updated and powered by battery.

Collision: When two or more devices on a network attempt to send data down the same channel at the same time.

CPU: Central Processing Unit. The "brain" of the computer. Plugs into the motherboard and performs all the processing functions for the hardware and software in the computer.

CRT: Cathode ray tube. The same technology used in most televisions, this is also currently the most popular technology used in monitors. A cathode at the back of the tube emits negatively charged electrons, which a positively charged anode attracts and accelerates into an electron beam. Magnetic steering coils around the tube help disperse the beam, spreading the electrons out. The electrons hit the inside of the tube, which is coated with phosphors, which generate light when hit. The colors of the light depend on the electrons that hit them, and can be red, green or blue. Because of the magnetic properties of the electrons, this is why you get a distortion on a CRT screen when you move a magnet near it.

Desktop: Generic term used to describe a computer that is used at a desktop, as opposed to a handheld PC or a laptop. Coined from the era of computers whose case was physically located on the desktop with the monitor sitting on top of it. Also used to describe the workspace area that can be seen on a Windows computer when no windows or programs are open on the screen (the screen with all your icons, where your background picture is would be referred to as "the desktop").

Driver: A piece of software that allows the operating system to communicate with a hardware device or peripheral.

Drive: A data storage device, such as floppy drive, hard drive, CD-ROM drive. Generally assigned a drive letter in the computer, such as A: (commonly used for the floppy drive), C: (commonly used for the primary hard disk drive) and D: (in single-hard disk systems, commonly assigned to the CD-ROM drive).

Drive letter: A letter used to represent a logical drive. I say "logical" drive because a drive letter does not always represent one physical disk. If a disk has more than one partition, then there may be multiple drive letters associated with that physical disk. For example, if you had a 80 gigabyte hard drive that consisted of one 80 gigabyte partition that was called C:, then the C: drive represents the entirety of the space on that physical drive. However if the same drive had two 40 gigabyte partitions, with C: being the first one and D: being the second one, even though in Windows you would see two separate drive letters (logical drives), they are still both parts of the same physical disk drive. Prior to Windows 95 home users could not have partitions larger than 2 gigabytes, so if you bought a 6 gigabyte drive you had to have it broken into three 2 gigabyte partitions. You no longer have to do that (see FAT for more information).

DVD-ROM: Just like a CD-ROM, only it can read both audio and data CDs and video and data DVDs. This term can be used for either the media or for the drive itself.

DVD-R/DVD+R: Recordable DVD storage media. Two competing technologies, not much difference in what they do or how they do it, though there are some compatibility issues when playing in DVD players. Some players like -R media, some like +R media. The only way to know for sure is to try one in your player. This term can be used for either the media or for the drive itself (also called a burner).

DVD-RW/DVD+RW: ReWritable DVD storage media. Again, there are two competing DVDRW technologies. DVD-RW and DVD+RW. Depending on what you will be using the disc in you may need one format or the other. All of my devices (PlayStation 2, Sony DVD player, Pioneer DVD Player) will play media of either type, and my DVD burner can use either media. This term can be used for either the media or for the drive itself (also called a burner).

ESD: Electro Static Discharge. Very important when building a PC, ESD is the biggest cause for failed components when people build a PC. You know when you walk across a carpet and touch a metal object and get a static shock? That's way more electricity than is needed to fry a circuit board. For this reason you should NEVER hold a circuit board while walking across a room. Carry it in a static bag (most components will come in one) or--in the case of PCI or AGP cards--carry it by the metal backpanel. When working on a PC, you should have a ESD wrist strap (available at any Radio Shack for a couple of bucks) which has a wire connected to an alligator clip that you can attach to the case. If you plan on doing a lot of PC repair, investing in a workmat for your floor is a wise choice. Of course, you could always kick it old school and ground yourself on the PC case before touching any internal components (and maintain contact with the case throughout), though this should be a last resort.

Ethernet: A network architecture developed by Xerox, Digital Equipment Corp (DEC) and Intel in the late 70s, it is currently the most widely used local area network (LAN) standard. Supports transfer rates of up to 10Mbps (10 megabits per second). Also referred to as 10Base-T.

Fast Ethernet: A newer version of Ethernet, supporting speeds up to 100Mbps (100 megabits per second). Also referred to as 100Base-T.

FAT: File Allocation Table. Written by Bill Gates in 1976, FAT is a table containing the location of all the files on a disk. As data is written to the disk it is written in many pieces and thrown all over the disk. The FAT allows the operating system to locate all of these pieces and put Humpty Dumpty back together again. Has two versions, FAT16 which--using a 16-bit table--can partition a drive up to 4 gigabytes, with 2 gigabytes per partition, and FAT32--using a 32-bit table and introduced in Windows 95--which supports drives up to 2 terabytes in one giant partition.

FDISK: Utility provided by Microsoft in MSDOS and versions of Windows prior to Windows XP to partition the hard disk so it can be formatted.

Firewall: Either a physical hardware device on a network or a software application installed on a computer that is designed to keep out any unauthorized traffic. In the case of software applications also the cause of many internet-related problems customers have--though it is still recommended to have one!

Floppy drive: While the disks that most of us are familiar with aren't exactly "floppy", the term is derived from the difference from hard disks, in which the magnetic media upon which data is stored is a solid disk. Even though it's a small hard plastic disk you're putting into the floppy drive, if you were to open the disk up you would find a small round disc of flexible film inside, not unlike the material in a cassette tape.

Format: An operation performed by the operating system that erases the file directory on the disk, checks the disk for errors, records bad sectors (if any) and creates a new, empty directory of files. Note that this does NOT destroy the data on the disk; it only makes it so when the operating system looks at the disk it sees no data. This is why there are so many "undelete" programs out there--data is not actually destroyed until the sector containing the data is overwritten.

GB: Gigabit (when spelled with a lower-case B, such as Gb) or gigabyte (when spelled with a upper-case B, such as GB). Giga means "a lot". Ok, giga means billion, so one gigabyte is one billion bytes, or one million kilobytes, or one thousand megabytes, blah blah blah I hate math, except when it's easy like this.

Gigabit Ethernet: The newest Ethernet technology, offering speeds up to 1Gbps (1 gigabit per second, or 1,000 megabits per second).

GUI: Graphical User Interface. An alternative to CLI, making it easier to manipulate objects on-screen, such as menus.

Hard Drive or Hard Disk Drive (HDD): Often misnamed "memory", the hard drive is the primary mass storage media in a computer. Data is stored there long-term. Also can be referred to as magnetic storage--as opposed to optical storage such as CD-ROM and DVD drives--as magnetism allows the reading and writing of data to the drive instead of a laser.

Hertz: A measurement of electrical frequency representing one electrical cycle per second. Used to measure the operating speed of different devices (busses, CPUs, memory, etc).

Hop: When a packet moves through a routed network such as the internet, it has to go through several connections to get where it's going. Each time it moves from one connection to the next, a hop occurs. For example, if you're on a dialup connection, when a data packet leaves your computer and goes to the modem chassis you're dialed into, that's one hop. The packet then goes from the modem chassis to the router or switch it's plugged into, which is another hop. Then from that router it may go to the boundary router, which is the router that connects the ISP to the rest of the internet, which is another hop, and so on. The fewer the number of hops, the faster your connection should be. However, if any of the hops between you and the remote host are overloaded, congested, or experiencing any problems, your connection will suffer. The traceroute utility is used to determine which hop is causing the problem.

Hub: A network device that connects multiple network devices together. When a packet arrives on one port it is sent out all the other ports on the hub so all devices see all packets. Not recommended networks of more than 5 computers if there is a lot of data traffic going on between computers. There are also switched hubs which are much more desirable, as they look at the destination of the packet and send it only out the port needed to get to the destination.

IDE: Integrated Drive Electronics. This is the interface that most hard drives, CD-ROM and DVD-ROM drives are connected to.

Integrated: In hardware context, used to refer to features that are included on the motherboard itself that would otherwise require a separate hardware device, such as a video card, sound card, or network card.

Internet: Created to allow multiple networks around the world to talk to each other, and originally used by both the Department of Defense and connecting universities to each other, the Internet is the largest network ever. Also referred to as the World Wide Web, the Internet is a great deal more than just websites. Email, file transfers, and all sorts of other information flows over the internet.

IP: Acronym for internet protocol, IP is a format for data packets. IP networks typically combine with TCP (transmission control protocol) in order to deliver IP packets to their destination. IP works very similar to the postal system, where you address a letter and drop it in the box. There is no physical connection between you and the recipient, but the letter gets there. IP addresses the packet and puts it in the system, but it is TCP that establishes the link to the recipient and allows the data to go back and forth. The term IP is also often used to refer specifically to an IP address.

IP Address: Every device on a IP network has an IP address. This address has to be unique on a network. If more than one device share the same IP address, address contention occurs and only one device can work at a time, often resulting in both devices being unable to communicate on the network. In standard IP networks, this consists of a number in the format X.X.X.X, with each X being a number between 0 and 255. The Internet Assigned Numbers Authority (IANA) has reserved several ranges of IP addresses specifically for use on local area networks. These IP ranges include 10.x.x.x, 192.168.x.x and 172.16.x.x, 172.17.x.x, 172.18.x.x and so on up to 172.31.x.x.

Jumper: Jumpers are metal bridges that close an electrical circuit. Generally a plastic plug with metal inside it, the jumper fits over a pair of metal pins. When the metal bridge is between the two pins, the circuit is closed. When it is removed, the circuit is open. Used on motherboards and other hardware devices to change the configuration of the device.

KB: Kilobit (when shown as Kb) or kilobyte (when shown as KB). One kilobit is one thousand bits, while one kilobyte is one thousand bytes (which would be 8,000 bits). However things get tricky when you're using a computer to count. Due to the way bits and bytes work, 1 KB is actually 1024 bytes. It's weird. Don't try to understand it, as you'll just want to hurt someone, and it might be me.

LAN: Local Area Network. A group of two or more computers, whether in a home, office, or university, directly connected to each other using network cables or short-range wireless equipment.

LCD: Liquid crystal display. A technology used in everything from watches to alarm clocks to microwaves to notebook computers, LCD screens are comprised of two sheets of polarizing material with a liquid crystal solution between them. Electrical currents pass through the solution causing the crystals to align, either blocking light or allowing it to pass through.

LED: Light emitting diode. Lights up when electricity passes through it. This is what you likely have on your alarm clock. This is also what the lights on your computer are.

Malware: Short for malicious software, any program or application that is designed to disrupt or damage a computer system. Worms, trojans and viruses are all malware, and spyware/adware is often considered malware as well.

Magnetic Storage Device: A device that uses magnetism to change the data bits on the surface of a specially created disk. Floppy disks, hard disks and cassette tapes fall into this category.

MB: Megabits (when spelled with a lower-case B, such as Mb) or Megabytes (when spelled with an upper-case B, such as MB). Mega means million, so one megabyte would be approximately one million bytes. Or it could be one thousand kilobytes. Math is fun!

Memory: Often used by people (inaccurately) to refer to the hard drive, system memory is where data is temporarily stored so it can be manipulated. Once changes have been made to the data, it is saved back to the storage media.

Modem: Stands for modulator-demodulator. Used by computers to take the digital data stored on them and transmitting it over telephone or cable lines (modulate), where it is received by a digital device at the other end and either processed by a device there or sent on via digital means, such as the internet (demodulate). Can be an external device that plugs into a serial port, USB port or ethernet card, or can be an internal device (generally the case with dialup modems) inserted into one of the slots on the motherboard.

Motherboard: Also knows as the mainboard or mobo, it's the main logic board (MLB) for a computer. It consists of a printed circuit board (PCB) and contains all of the connectors that your hardware components plug into. It allows power to be distributed to all devices and is in charge of communication between devices.

OEM: Original Equipment Manufacturer, pronounced just as you'd spell it (oh ee em). OEM can be somewhat misleading since many OEMs are not actually the original equipment manufacturer. OEMs build PCs, customize them, and sell them under their own name. Dell, Compaq, Gateway, HP, Packard Bell (may they rest in Hell), eMachines, all are OEMs.

Operating System: A program or set of programs that allow a computer to accept input, process that input, and generate output. Windows is an operating system, as is Mac OS (hey, guess what OS stands for?).

Optical Storage Device: A device that uses a laser to change the data bits on the surface of a specially created disk. In the case of CD-ROMs or DVD-ROMs, the laser can only read the bits.

Packet: A piece of a message transmitted over a packet-switched network. Contains data for the message and a header that contains the destination of the packet so routers or switched hubs know where to send the packet.

Parallel Port: Also commonly referred to as a printer port, parallel ports can transfer data 8 bits (or one byte) at a time, as opposed to serial ports, which can only transfer one bit at a time.

Partition: As a noun, it is the physical allocation of disk space on a drive. One hard drive can be one large partition (for example, a 160 gigabyte drive could have one 160 gigabyte partition) with a drive letter associated with it (such as C:), or it can be broken up into several smaller partitions (such as two 80 gigabyte partitions, or four 40 gigabyte partitions) each with their own drive letter (C:, D:, E: and F: for example). As a verb, it is used to represent the act of creating a partition or partitions on a drive.

Ping: Named for the sound a sonar makes, ping is a utility developed to check if a particular IP host is reachable from another IP host. When pinging an IP address, the host sends a packet of data addressed to the remote host and then waits for a reply. How long it takes to get this reply can be used to determine if there are problems in IP network connectivity. When used in conjunction with the traceroute tool, the location of that problem can often be identified.

POST: Power On Self Test. The first thing you see on a computer (unless you have some OEM machine that spews their logo all over the screen and hides it). At this time the computer's BIOS checks to make sure if the computer's memory, disk drives, peripherals and other hardware components are working properly. Once it has determined this, the computer starts the boot process. If there is an error, the computer will beep at you. The configuration of the beeps (how long they are, how many there are) tells you what the problem is. A list of POST codes can be found at http://www.bioscentral.com. Just choose the BIOS manufacturer from the list.

Power Supply: Shockingly enough, the device that supplies power to the computer. Mounted inside the case, power cables plug into the motherboard, IDE devices, floppy drives, and anything else that has a plug that the power supply cables will fit onto.

Reboot: The act of turning the computer off and back on again. Some people mistakenly use this term in place of "reload" or "re-install", when they actually re-install the operating system of the computer. I've had many customers tell me they can't get on the internet since they rebooted, making me think there's a problem with their computer or their settings, when in fact they reinstalled Windows and just need their connection set up again.

Registry: Where Windows stores all it's configuration information. If your registry goes bye-bye, so does Windows.

Ribbon cable: The cable that your drives use to connect to your motherboard. Called a ribbon because it is wide and flat, there are also rounded cables that help with airflow within a case. Years of calling them "ribbons" has stuck. Maybe that'll change in a few years.

Router: A device that forwards--or routes--data packets along networks. Routers have connections to at least two networks, typically two LANs or WANs, or a LAN and an ISP. Routers are often also called gateways, as they are the doorway from one network to the next. And for the record, it is pronounced in a way that rhymes with chowder, not shooter.

Serial port: Also referred to as a communications port or COM port, the serial port can transfer data at 1 bit at a time (though many thousands of bits per second), and because of this it is used primarily for data communications. If a bit fails, it is resent, helping to ensure there is no loss of data.

Slot: Any of the locations on the motherboard where an interface card is plugged into, such as a video card or memory module. Can also be used to refer to the openings in the back of the computer case where such cards would be accessed.

Socket: Typically used to refer to the slot where the CPU plugs into the motherboard.

Spyware: Any application that gathers information about the user behind the scenes, without the user knowing it. This information is often sent back to the spyware maker, often for advertising purposes (spyware is used in many adware applications). While this information is generally harmless, the term spyware also includes malicious programs that gather email addresses and personal information such as social security numbers and credit card information. Often installed piggy-backed on a program that a user downloads from the internet and places on their computer (whether they know it or not).

TCP: Transmission Control Protocol. TCP establishes the data connection between two hosts that allows packets to pass back and forth between them. Unlike UDP, TCP guarantees delivery of the data (if a packet gets dropped it is resent) and guarantees the packets will be received in the order they are sent, making it the protocol of choice for any network with critical data transmission requirements such as voice or streaming audio/video.

Tower: A type of case named for its orientation, which is standing up like a tower as opposed to laying down on its side like the older traditional desktop PC. Comes in varying heights, such as micro tower, mini tower, mid tower and full tower.

Trace or Traceroute: An IP utility created to determine where a network slowdown or outage is occurring. The tool traces a packet from the host computer to a remote IP host, displaying how many hops the packet needs to take and the time between each hop. Whichever hop has the longest time value, that's where your slowdown is occurring.

Trojan: Also called a trojan horse program, because it looks and acts like a benevolent program, when in actuality it is either causing harm to your computer directly or allowing your computer to be harmed by other applications. A common way to get a trojan horse is to click on pop-up ads that claim to protect or rid your computer of viruses or spyware, when in fact installing the application either places such programs on the computer or makes the computer vulnerable to them (such as disabling your antivirus software).

UDP: User Datagram Protocol. A connectionless protocol, packets are pointed to a destination and fingers are crossed, hoping they get where they need to go. Unlike TCP, UDP has little to no error-correction or recovery services. Generally used for non-critical communication or broadcast traffic, such as ARP broadcasts.

USB: Universal Serial Bus, a data communication standard developed for ease-of-use and high bandwidth transfers, USB devices are hot-swappable (meaning they can be plugged in while the computer is turned on) and--especially with USB 2.0--can transfer data up to 12Mbps.

Virus: Just like real viruses invade our body and attack our cells, computer viruses invade your computer and attack your data. Viruses are typically spread via email attachments or attached to downloaded programs. Commonly used to categorize any malicious software that is installed on your computer without your permission, the term virus is specifically used for the kinds of viruses that require user intervention in order to infect your computer (i.e. opening an email or email attachment, running a program, etc.). Klez, Beagle/Bagle, and MyDoom fall into this category. Some viruses also contain worms as part of their payload. It is important to know that antivirus software can only protect you from worms and viruses it knows about. Failure to keep your antivirus software up-to-date negates the purpose of having the software.

Worm: A specially crafted kind of virus that both infects vulnerable computers and replicates itself without any intervention by the user. Blaster, Welchia, Sasser and Gaobot are all worms.