What is different between simplex,full duplex and half duplex

Simplex

Simplex communication refers to the mode in which data transmission can only be transmitted in one direction. For example, point A can send information to point B, but point B cannot send information to point A. For example, before the traffic lights, the signal lights are only responsible for sending signals of three colors, and pedestrians and vehicles on the road can only accept this information, and can not feedback.

This type of communication is less efficient due to its inefficiency. 

Full Duplex

Full-duplex communication is the opposite of simplex communication. Point A can send information to point B, point B can also send information to point A, and both parties can send messages to each other at the same time.

The advantage of this type of communication is that the efficiency is very high, but the disadvantages are also obvious. Both the receiving end and the transmitting end need to have the ability to receive and transmit information at the same time.

But the way humans process information is single-threaded, meaning that receiving and sending can only process one of them at the same time.

The advantage of half-duplex at this time is reflected.

Half duplex

Half-duplex mode of operation is similar to full-duplex, but because it is "half" duplex, it is definitely different from full-duplex.

The same point is that point A can send information to point B, and point B can also send message to point A.

The difference is that half-duplex does not allow two points to simultaneously send messages while receiving messages, and can only transmit messages in one direction at the same time.