A protocol is the rules required by different applications for the exchange of data where the application can perform actions such as running commands on remote systems, sending and receiving email, or maybe downloading files from the internet. Each application has a special port number it uses for communication. If you think of ports as being TV channels, if we want to watch sport we go to the sports channels, if we want to watch news we go to the news channel. Applications are the same; if we want to send an email, we use a mail application, and they all have a distinct port number for communication.
There are two types of ports: Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). The main difference between the two is that the TCP is connection-orientated as it uses a three-way handshake, and...