The motherboard

RAM/DDR socket: The main purpose of the RAM socket on the motherboard is to attach the RAM to motherboard. The RAM is needed to be put into the socket for the computer to be able to function effectively and efficiently, this is as the data that the cpu need to process to complete a instruction is stored on the ram.

CPU socket: This is the socket on the motherboard that you use to connect the CPU(central processing unit) to the motherboard. Depending on the motherboard and the brand of the CPU(amd or intel) the pins could either be on the CPU socket on the motherboard or on the CPU itself.

PCI slot: The PCI slot is used to add expansion cards to the motherboard to allow the computer systems to access addtional feature or enchance other features. For example you could add a wireless card to the computer system so that the computer systems is able to connect to network without the need for a physical connection. You could put a NIC(network interface card) in to the PCI which offer greater bandwidth if you want to get as much data as possible. This may be useful to gamer who plays competive online games.

PCIe x1: You use this just like the PCI in the fact that you use it to add expansion cards to the motherboard. but the reason why one may use this over a regular PCI slot and why it's on motherboards at all is because of the fact that it offers much greater speeds than a regular PCI slot.

PCIe x16: The PCIe x16 is used to add GPU(graphical processing units) to the motherboard. You can add a wide variaty of GPU with differing processing power. The most powerful GPU on the market today are mainly used by gamers today to play games on the highest possible graphical settings and with a very high FPS(Frames per second). The more high-end GPU's also allow you to play games and video at 4k.

SATA port: The SATA port is used to connect a SATA cable via a SATA connector to the motherboard so that the computer system is able to get data off the storage medium.

ATX/Power socket: This socket on the motherboard is used to connect the psu to the motherboard to the PSU via a ATX/power connector. This is need obliviously so that the computer system has power and can actually function and complete tasks. An ATX socket also come in different forms, for example there is a 4-pin connector to power the CPU and also the motherboard will also most likely have a 24-pin connector on the motherboard as well.