IP address is a unique identifier in a computer network. No IP address, the computer can not access the Internet.
IPv4 addresses 32bit, in dotted decimal notation, such as 202.38.64.3
IPv6 address 128bit, with a colon-separated hexadecimal notation, such as 2001: da8: d800: 1075: 5813: f666: 5737: 3
Port is used to distinguish between the transport layer service used for a positive integer of 16bit. For example, port 80 is the web service, port 23 is telnet service.
Find computers by IP address, find the service process on the computer through the port.
A complete inter-network communication process needs to identify a quintuple: source address, source port, protocol, destination address, destination port