Card slots on the computer motherboard are used for additional cards like sound cards, video cards, network cards, internal modems into the board. There are some motherboards today that include video and sound without the addition of an extra card. These cards slots today are mostly PCI type card slots.
The cards that are plugged into a computer are the expansion bus. The expansion bus is a means of a microprocessor extending its communication ability further into the outside world. It is a data exchange means between add-on cards and the microprocessor and the motherboard. There had been many types of expansion buses.
Read: Computer Motherboard
ISA – Industry Standard Architecture. Used when the original 8088 8-bit microprocessor-based personal computers were produced.
EISA – Extended ISA used when the 80286 through 80486 series microprocessors were being produced. This bus is still used but is being phased out and is almost gone today.
MCI – Micro-channel architecture by IBM and used mainly on IBM brand computers.
PCI – Peripheral Component Interconnect. The popular expansion bus of choice, it is significantly faster than EISA.
AGP – Accelerated Graphics Port. This bus is developed for fast video cards. It is currently upto 4x mode speed.
The current popular expansion bus is the PCI (Peripheral Component Interconnect) bus for all cards except the graphics cards. For graphics cards, the bus of choice is AGP. Most motherboards today have one AGP slot and several PCI slots.
Also Read: Computer Components