AKA Chassis: This is the body for your system. There are several types and styles. Styles include desktop, mini-tower, mid-tower and full-tower. Generally speaking, the bigger, the better the airflow and cooling inside. I prefer the mid-tower. 300W is typically the minimum power supply that I recommend.
AKA Motherboard: This is the central nervous system of the PC minus the brain. Everything your PC does passes through this component. There are several types to choose from: Socket-A, Socket-754, Socket-940, Socket-603, Socket-478, etc.; Simply put, Socket-A/754/940 are only for AMD (the Athlon) and Socket-603 and 478 are for Intel Pentium 4 CPU's.
This is the brain of your PC and plugs into your mainboard. When you see that a PC is advertised as X.x Gigahertz (GHz) the number of GHz refers to the speed of this piece. AMD has recently gone back to a performance number that exceeds the actual GHz of the CPU and is supposed to compare directly to Intel's CPU speeds.
Random Access Memory is the valet parking staff of your PC. The more, the better, because you wait less. The operating speeds of RAM are determined in nanoseconds as compared to milliseconds for a HDD. There are several types of RAM and it's important that you get the kind that matches your mainboard. The most common types are SDRAM DIMMS and DDR DIMMS. Generally, the higher the number the better.
This is the part that your monitor plugs into, and in some cases can be included as part of your mainboard (integrated). There are a number of different factors involved in buying a video card. First, the amount of memory on the card - it ranges from 4MB to 256MB. Second, resolutions supported - the higher the resolution, the more you can fit onto your screen, which is especially important w/ monitors 17" and up. Third, 3D support - this is very important with today's computer games. If you , or any kids using the PC, never plan to get any games like NASCAR, Quake or Tomb Raider, you don't need much, if any, 3D support.
Hard disk drives are where all your data and programs are stored. Right now, the smallest generally available is a 3.2GB - enough to store about 700 million words of text. You can get them as large as 200GB now. If you've used a computer, every time you see the light flash or here your PC make a sound and it's not the CD-ROM, that's the HDD. The bigger and faster, the better.
LS-120/SuperDisk/Zip/Jazz/pen drives: All are types of removable media meant to supplement or replace 3.5" floppy drives.
Standard CD-ROM reads program and audio CD's. Most now shipping are "multi-read" models which can also read re-writable CD's produced by certain CD recorders. CD ReWritables (CD-RW) are also available and let you make your own CD's.
Keyboard and mouse. This is a personal preference kinda thing that you can spend anywhere from $12 to $150 or more on.
Practically a requirement these days, a sound card is what you plug the speakers into. Starting at $20 on up to almost $200 for a gamers' choice card accompanied by speakers ranging from $12 "good enough" to $210 for a near theater quality audio experience consisting of 5 speakers and a sub-woofer. The sound is another part that can be found integrated into the mainboard.
Current standard is 56k using v.92 protocol. They come with or without voicemail and/or speakerphone capabilities, internal or external. Unnecessary if you are planning to get a cable modem or DSL through your phone company. I would never recommend a winmodem or softmodem (any type of modem that has a minimum CPU or MS Windows operating system requirement).
See Sound above
Considerations for monitor include size, resolution and refresh rate. Current standard size is 17", LCD is really gaining on the traditional tube type monitors. Minimum dot pitch I recommend is .28mm. In the case of dot pitch (resolution), smaller is better. Finally, the higher the refresh rate on a CRT type, the easier on the eyes.
The questions are laser or inkjet and color or b/w. Prices range from $50 to $400 for most users.
Can't have a PC without basic software to run it. If you're going PC and not MAC, Win XP (either Home or Professional) is for you unless you're adventurous or anti-Microsoft, then try a flavor of Linux.
Once this was a luxury supplement for hard-core gamers or 3D modelers, but now it's included in nearly all video cards that you can buy.
Uninterruptable Power Supply - the more you depend on your machine, the more you need one of these devices to feed clean, continuous power to your system. Having one of these allows you several minutes to power down your system in the event of a power outtage.
Digital Versatile(Video) Disc - A substitution for, or an addition to, a CD-ROM. The DVD-ROM's read DVD's which contain programs or movies. The DVD-RW's also write to CD's or DVD's.