For example I do not need to go out to dinner with friends and each time the newspaper's name and contact information with friends you know who I am this is stateful
And I went to the business lobby staff do not remember every time I have to fill in who is going to present a photo ID that is stateless
Stateless protocol: Remember the next link does not link this time.
HTTP, UDP is a stateless protocol
TCP, FTP protocol is stateful