The motherboard is just a part, just a board. According to the function, there are the following things (in terms of hardware that can be more common today, don't say too old):

Slot characteristics:

The previous generation CPU socket was 478/939 pin, and now it is AM2/775.

Memory slots are generally 2-4 DDR/DDR2.

Graphics card slot is generally 1-2, and AGP/PCI-E slot.

Storage slots are generally IDE and SATA interfaces. IDE is a very long one, which can connect hard disk and CD-ROM. SATA is very small, and USB is almost as big, because there are few SATA optical drives, and they are usually connected by hard disks.

Chip aspect

The one near the CPU, usually with a radiator, is the North Bridge, which is responsible for managing some core tasks, such as coordinating CPU/ memory. If CPU is the breadwinner, Northbridge Chip is the housewife (-|||).

Southbridge chip manages some simple tasks, such as sound card and network card. Kind of like a nanny. NV's chipset generally has no south bridge, and all the controls are on one chip (meaning that women are in charge of too many things).

Integrated sound card and network card chip. It's small and hard to find, but there's no need to find it.

BIOS The BIOS on some motherboards can be removed. This thing is a chip with programs written on it. According to the previous metaphor, this is a family rule. Memory depends on the battery, and you can also see it on the motherboard.

All that's left is an auxiliary chip.

Interface aspect

There will be a row of interfaces on the back of the motherboard near the chassis. The basic output of the motherboard is above, such as USB, serial port, parallel port, network cable, interface of integrated graphics card, audio input and output of integrated sound card, etc. Some motherboards will also have 1394 firewire and SPDIF digital audio output.

There are also some small interfaces on the motherboard. For example, the USB leading to the chassis panel and the front panel output interface leading to the chassis panel power switch/restart switch/power light/hard disk light are all needle-shaped in appearance.

Electrical materials, inductance and capacitance, etc. The inductor is a circle with copper wires around it. It is also closed and looks like a square. The capacitor is chimney-shaped. These things can be seen whether the motherboard is made of thick materials, and the life of solid capacitors is longer than that of liquids, but there is no need to blindly pursue them.

There are also power slots that are generally 20+4, and some are only 20.

Depending on the wiring, it may not be possible to directly see the direct connection between each component and the chip. You can refer to the illustration of the chipset.