These are the different sizes and varieties of mother boards developed over the years.
The Motherboard is the central backbone to which all other modular parts such as RAM, Hard drives, etc. can be attached. It accepts various components (PCI cards in particular) for the purposes of customization and upgrading. One of the main purposes is to distribute power to many of the PC components including the (CPU) processor itself. It electronically coordinates the operation of all devices. It also coordinates the processing between devices.
Mostly the mother boards got smaller and more efficient over time. Their speeds became faster as their size got smaller. Some of the form factors are (From largest to smallest size): Standard ATX, Micro ATX, Mini ITX, Nano ITX and Pico ITX. In most desktop computers the Micro ATX is very popular.
Integration became the standard. In the earlier mother boards it was common to have a separate Graphic card, Audio card and modem. Many other cards and devices were available also. In recent boards almost all of these are now integrated.
Cost also became a factor in purchasing computers. As the mother boards got smaller the prices started dropping. By about 2005 you could purchase desktop computers for around $500. Laptops took a while to catch up but by 2008 they also became inexpensive.
Speeds started getting faster and faster. Due the demand of gaming and high level applications the need for speed needed to be greater. Some of the speeds (fastest to slowest) are as follows: 1066 MHz, 800 MHz, 533 MHz, and 400 MHz. Certain manufacturers made other speeds.
If you are going to purchase a mother board for any reason you must know what you are going to use it for. If you are using a particular case it must be able to fit. You must know what processor you are going to be using. Another big thing to know is what kind of Graphics need you want. This, in itself, will drive up the price of the board. If you want to do gaming you must know what kind of game you want to play and what the system requirements are. You need to know if it is compatible to your processor. That means you need to know if you are going to use an INTEL or AMD as an example.
Check more than one source if you are going to purchase a mother board. THE MAIN THING!!! If you don’t understand what to do find somebody that does. You can spend a lot of money needlessly if you don’t. It’s very easy to damage a motherboard. Even a little static electricity can render it worthless.