The motherboard is a large circuit board that ties together all the components that make up a computer. It is also the home to your CPU and memory, but these do not come with the motherboard. However, a motherboard is designed for a particular type and manufacturer CPU.

The size of the motherboard indicates whether it will fit in the desired case (a micro-ATX, or mini-ATX, or full-ATX motherboard will fit in a full ATX case, but a full-ATX motherboard will not fit in a micro-ATX case). It also determines how many expansion cards, and what kind, can be supported (the case may have more holes for expansion cards than the motherboard will support). And, finally, it determines the maximum amount of memory the computer can access, in the form of memory slots. (4 slots that can each take a maximum 8GB memory stick allow 32GB of memory.)

If you are building your own computer, you'll want a motherboard that comes from a reputable manufacturer, such as ASUS or Gigabyte. And you'd want to pick one that supports your favorite brand of CPU, such as Intel or AMD. (I prefer AMD.)

Motherboards also have speed. That is, there is an onboard clock; everything a computer does is based on the ticking of that clock. Each tick does one thing, so the faster the onboard clock ticks, the faster your computer can run, as long as the CPU and memory you buy can keep up. (Otherwise, the slowest component becomes the bottleneck.)

When Good Motherboards Go Bad

Generally motherboards are fairly stable pieces of equipment. If it works when you get it, it will probably work forever…unless it gets fried by a voltage surge (lightning?), or drowned by floodwaters, or baked by excess heat. If your motherboard fails, though, you'll have to get a new one…and don't forget, you'll probably also need a new CPU and probably new memory. So, new computer.