Stateless Vs Stateful Protocol

Network Protocols for client(web browser) and servers are divided into two types: 

1. Stateless Protocol

2. Stateful protocol. 

1. Stateless Protocol: 

In which, Client send request to the server and server response back according to current state. It does not require the server to retain session information or a status about each communicating partner for multiple request. 

Eg:

• HTTP (Hypertext Transfer Protocol)
• DNS (Domain Name System) 
• UDP (User Datagram Protocol)

2. Stateful Protocol: 

In which, Client send a request to the server then it expects some kind of response, if client does not get any response then it resend the request. 

Eg:

• TCP
• FTP (File Transfer Protocol)
• Telnet 

Source: geeksforgeeks.org