There are several ways to classify common PC motherboards:
1、According to the CPU used on the motherboard
386 motherboard, 486 motherboard, Pentium (586) motherboard, Pentium Pro (686) motherboard.
2、According to the type of I/O bus on the motherboard
（1） ISA (Industry Standard Architecture)
（2）EISA (Extension Industry Standard Architecture)
（3）MCA (Micro Channel)
（4）VESA (Video Electronic Standards Association)
（5）PCI (Peripheral Component Interconnect)
3、according to logic control chip components
These chipsets integrate the control of CPU, CACHE, I/0 and bus, and motherboards above 586 have paid particular attention to the role of the chipset.
（1） NX Neptune (Neptune), supports Pentium 75 MHz or higher CPU.
（2）FX has this chipset in both 430 and 440 series. The former is used for Pentium and the latter is used for Pentium Pro.
（3）SiS series.
（4）Opti series adopts fewer motherboard vendors.
4、according to the main board structure
（1） AT standard size motherboards, some 486 and 586 motherboards also use AT structure layout.
（2）The Baby AT motherboard is smaller than the AT motherboard. Many integrated motherboards of original machines first adopt this motherboard structure.
（3）ATX 127; The improved AT motherboard has optimized the layout of the components on the motherboard and has better heat dissipation and integration. It needs to be used with a special ATX chassis.
（4）The integrated motherboard integrates a variety of circuits such as graphics card and display. Generally, it can work without inserting a card. It has the advantages of high integration and space saving.
（5）NLX Intel's latest motherboard structure, the biggest feature is that the motherboard and CPU upgrades are flexible, convenient and effective
5、according to function
（1）PnP function The motherboard with PnP BIOS and PnP operating system (such as Win95) can help users automatically configure host peripherals. It can automatically enter the waiting and dormant state when the user is not using the host, reducing the power consumption of the CPU and various components during this period.
（2）Jumper-free motherboard This is a new type of motherboard, which is a further improvement to the PnP motherboard. On this kind of motherboard, even the type of CPU, working voltage, etc. do not need to use jumper switches, they are automatically recognized, and only need to be slightly adjusted by software.