When connecting computers, we need to know the protocols. These are logical, not physical.
Protocols are the same language used to connect different file types, different OS platforms, and communication devices. Suppose there are 3 people in Japan, so what language do we use to understand each other? English is an international language, and protocol is a computer language that was created to help computers communicate with each other around the world.
IP Address
You need to understand IP addresses in order for computers around the world to connect properly. An IP address is 32 bits and is divided into four 8-bit sections by a dot. Each 8-bit section is called an individual byte or octet. Valid values range from 1 to 254 and must be reserved for 0 and 255. 0 is the network address and 255 is the broadcast address.