PC600/800: A rating that certifies that the memory is capable of running at 600 or 800 MHz bus. This memory is generally required for running at those specific speeds.
PCI/PCI-Express: "Peripheral Component Interconnect" is a high-speed connection for devices including SCSI cards, video cards, sound cards, modems, and video capture cards, etc. This is the primary way of adding devices to your computer. It is faster than ISA, so is preferred for devices such as sound cards and SCSI cards. PCI is slower than AGP (graphics port only) but PCI-Express is the fastest now available. Default PCI speed is 33 MHz just like AGP but the express has a 64bit pipeline increasing data transfer rates.
Power Supply: Generally this comes with the case. It can have an AT or ATX power connector and it is measured in its rated output. It converts power from your outlets into a steady stream of power the computer can use. A 300 or 350-Watt power supply is generally sufficient for home users, but power users may need a 400 or 500 Watt power supply if they have a lot of hard drives or other components. The quality of power supply can be very important and may make the difference between a stable computer and a computer that crashes often.
PPGA: This stands for Plastic Pin Grid Array. PPGA is the same as Socket 370 and is a relatively new CPU connection type. The CPUs are very similar to the Socket 7 CPUs, but they cannot be used in the same motherboards. Like the Socket 7 CPUs, they have pins at the bottom of a flat square CPU, and sit parallel to the surface of the motherboard.
Printer: A printer outputs data that is seen on the computer screen. Most printers are used through a parallel port, but some newer ones use USB connections. USB is somewhat faster, but there's not much of a difference for printers. Networked computers usually print to a printer through the network card. The most crucial printer measurement is its dots per inch rating. Although this can be misleading, a higher number is generally better. Printers are best chosen by actually seeing the quality of the printer output.
RAM (Memory): This is the component that holds recently accessed data for the CPU to have quick access to. It is much faster than reading from a hard drive, so having a lot of RAM makes it quick to retrieve recently accessed files, applications, and other data. All programs must be run through RAM before they can be used. RAM stands for Random Access Memory and is typically measured in megabytes.
RDRAM: This is the Intel-backed form of memory that is competing with PC133 SDRAM. It boasts speeds up to 800 MHz for very high bandwidth, but whether or not it will be worth its high price is a tough call. RDRAM comes in RIMMs, which will not fit in the BX motherboard DIMM slots.
Refresh Rate: This is the speed at which the monitor's picture is redrawn or flashed in front of your eyes. Slower refresh rates provide a noticeable flicker. Higher refresh rates create a steady picture (and is easier on your eyes). The refresh rate is determined by the video card, but also must be supported by the monitor. The maximum refresh rate will be different for different resolutions. A minimum of 75 Hertz is recommended (TV refresh rates are 30 Hz, which is why there is a noticeable flicker).
Resolution: Similar to DPI, the resolution is how many pixels can be displayed on the screen at once. The resolution is measured in the number of pixels wide and high that the display is. The most common resolutions are 640x480, 800x600, 1024x768, 1280x1024, and 1600x1200. Higher resolutions provide sharper, better quality pictures, but also make type and images smaller since more information is squeezed onto the same size screen. The size of the monitor is important when considering the resolution. A 14" or 15" monitor is best with an 800x600 resolution. 1024x768 is best for 17" monitors. 19" monitors can use 1280x1024 or 1024x768 well. 1600x1200 or greater is recommended only for 21" or larger monitors. The resolution of an analog TV screen is 512x400; another reason why a computer's display is much better than a TV's. Although, HDTV now reaches resolutions of 1280x720.
RIMM: A RIMM is a form of memory connection much like a SIMM or DIMM. RIMMs are physically different from the others and cannot be used on a BX chipset motherboard. RIMM stands for Rambus Inline Memory Module. RDRAM comes in RIMMs.
Scanner: This device allows you to read images and text into your computer. Scanners use a variety of connection formats including Parallel Port, USB, and SCSI. USB is simple, SCSI is fast, and Parallel Port is extremely slow.
SDRAM: This is the most common type of memory used today and is a type of DIMM. SDRAM (like all memory) is measured by its access time, CAS latency, its rating, and other timings. Recent ratings are PC100 and PC133, and this memory is required for newer Pentium II and III CPUs.
SECC: A Single Edge Contact Cartridge is a type of connection for the CPU to plug into the motherboard. It is the same as Slot 1. All Pentium II and III CPUs are Slot 1, as are some Celeron CPUs. These CPUs require a Slot 1 motherboard using the BX or LX (older) chipsets as well as newer ones. They plug into the motherboard much like a PCI sound card or other component would. Thus, they sit perpendicular to the surface of the motherboard.
Socket 7: This is an older CPU connection format that was used by the Pentium, Pentium MMX, all the AMD K6 and later CPUs, and several Cyrix CPUs. Slot 1 CPUs cannot be used on these motherboards, nor can Socket 370 CPUs. These CPUs are flat squares that sit parallel to the motherboard. Their pins plug into the motherboard.
SCSI: There are two types of interfaces for hard drives, CD-ROM drives, etc. One is SCSI while the other is IDE. IDE is much more common and less expensive. SCSI is more expensive and also more flexible and generally faster. With a single SCSI card you can have 15 or more devices whereas you are only allowed to have 4 devices with an IDE system. The fastest hard drives (and generally CD-ROM drives too) are SCSI-based. Examples are the 10,000 rpm IBM 9LZX hard drive. The fastest IDE drives run at 7,200 rpm. To have a SCSI-based computer, you have to have a SCSI card, SCSI hard drive, etc. SCSI is more complicated to configure and should not be taken on by amateurs. There is a variety of connections such as 25, 50, 68, 68 LVD, 80 SCA, etc. (where the numbers represent the types of connections.
SSE (KNI): Streaming SIMD Extensions represent a set of instructions integrated into Intel's Pentium III CPUs. Similar to MMX and 3DNow!, they are intended to speed up CPU performance. While MMX did not have much of an impact, SSE appears to offer significant improvements. SSE is the primary difference between the Pentium II and Pentium III CPUs. Tweaking: This is a term used to describe changing settings, adding programs, etc. in order to make your computer run faster or more efficiently.
UltraDMA/UltraATA: Also known as ATA/33, this is a technology in newer IDE hard drives that allows for greater overall throughput. ATA/66 is now available with many hard drives which is even faster. However, a 7200 rpm ATA/33 drive will generally be faster than a 5400 rpm ATA/66 drive. That is, the speed of the drive itself is much more important than the ATA/33 or 66 rating.
USB: USB stands for Universal Serial Bus and is a new technology theoretically capable of connecting a very large number of external devices on a computer. USB is intended primarily for low bandwidth (slow) components such as mice, keyboards, modems, joysticks, etc., but not fast devices like hard drives. USB has its benefits and its problems, which I will not go into depth about. Most computers have 2 USB ports. Some USB devices will have another port so that another USB device can be plugged into it. Otherwise you run out of ports quickly, in which case you may need a USB hub which will add more ports (usually 4).
UPS: This stands for Uninterruptible Power Supply, and it is a device that provides continuous, reliable power to your computer. It is a device that plugs into your outlets and you then plug your computer, monitor, and other components into. It uses a battery to make sure that the computer will stay on even if there is a power outage. These are generally used only for critical machines and servers, but they can also be useful at home if you have blackouts/brownouts or voltage irregularities. UPSs made by APS or Opti-UPS are generally good quality.
Video Capture / Output: This is generally achieved with a video capture card that is capable of taking video in from a TV or VCR and recording it to a computer video file. Usually a separate device is required, but some of today's video cards have this capability built in. If you want to be able to do this, be aware that your video card must support it, or you must have a video capture card. Computer generated videos can also be output to VCR tapes.
Video Card: This component is used to transfer data to your monitor so that it can be displayed. Today's video cards have a variety of "3D" capabilities. 3D video cards are only needed for playing games though. When playing 3D games, the video card is the most important component.
Voltage: This is the amount of power supplied to a component. CPU voltage is the only one that we ever have any control over. Increasing the voltage can be helpful in over clocking your CPU to a high speed. Most motherboards do not support this as an option though.