Most computers are made of many components that can be changed for better ones as time goes by. Here is a list of the common computer hardware components found on the market.
AGP Slot : Accelerated Graphic Port. This was introduced to allow the display cards to access the system memory directly without going through a shared PCI bus and allow a faster processing to accommodate the 3D games and other intensive display applications. There is only one and is usually a brown slot on the main PC board.
BIOS : Basic Input Output System. The bios is what holds the computer's configuration and will launch the PC boot sequence on power on. This is stored in a ROM on the main board and is usually accessed for modification using the DEL key before the computer loads the operation system.
BUS : This is a path on the motherboard to send data from/to peripherals, ram and cpu.
Cache Memory : This is fast speed ram used by the CPU to load data faster than standard ram. Some functions and data are stored in cache. Cache is found on the main board and in the CPU itself.
CD-Rom : This was the first Compact Disk standard that was used on computers to eliminate the used of 1.4 Floppy disks. They could hold 650MB and now up to 700MB.
CD-RW : This is a CD unit that can write to blank CD's to store data and be read on standard CD-ROMs.
CPU : Central Processing Unit. This is the brain of your computer and does all the work. It's what gets binary commands to execute with binary data. The faster the CPU, the faster the computer will be at running programs.
DVD-Rom : This is a cd that can read DVDs. A DVD can hold much more data than a standard CD and is mostly used to play movies. There are also some programs and games on DVD but are still rare.
DVD-RW : This is a DVD writer and like a CD-RW is used to write data on a blank DVD media. They are mostly used to make copies or movie DVDs or backup big amount of data.
FireWire : FireWire is like the USB ports but faster. These are mostly used for external hard drives, DVD writers, digital cameras, scanners... they are also Plug & Play.
Floppy Drive : Almost obsolete they are becoming an options on new computers. They can accept 1.4 MB of data and the media is sensible to magnetic fields. Most use a cd-rom or a USB stick to carry data to other computers.
Hard Disk : This unit is the data storage of your PC for your applications, user data and all that you put on the computer. The most popular are IDE and SCSI hard disks. IDE is used for personal computers and SCSI is used more for servers.
IDE Controller : This is what you connect the hard drives to. They are usually embedded on the main board. You can add a faster IDE port card and use it in a PCI slot to connect faster hard drives or have more than 4 IDE units.
ISA Slot : These were the oldest kind of slots that would take 8 or 16 bits cards. They ran at 8mhz and are still present in some computers for backward compatibility. Printer cards or serial cards and other slow devices use these.
Keyboard : This is what you use to type. Some keyboards have extra buttons to use internet explorer functions, open the calculator and other gadgets. There are USB and PS2 keyboards.
PS2 keyboard port
Modem : Using a phone line this device is used to connect on the internet, send fax or other remote connections. These are slow and replaced by cable modems or ADSL for internet connections.
Monitor : This is the display screen of your computer, it's connected on the VGA adapter of your PC usually with a DB-15 cable. There are standard monitors and LCD monitors.
Mouse : This is what is used to move the pointer on your display screen. Some use a ball that rolls on a pad, some use infra-red and some are also wireless.
Network Adapter : This is the card...