What is an Expansion Board?
An expansion board is a printed circuit board that you can insert into a computer to give it added capabilities, as by increasing memory or improving graphics.. Expansion boards are also called adapters, cards, add-ins, and add-ons.
Below there are two examples of expansion boards, one for I/O components and the other for memory expansion.
Expansion boards for PCs can be half-size (also half-length) or full-size (also full-length). Most PCs have slots for each type of board. A half-size board is sometimes called an 8-bit board because it can transmit only 8 bits at a time. A full-size board is called a 16-bit board. In addition, some expansion boards are designed to operate with a local bus, such as PCI.
In earlier PCs, all peripheral controllers were housed on expansion boards, including the disk controller, serial and parallel ports, sound and display. Today, all the peripheral control may be included in the chipset.