What is meant by formal and informal communication?

Informal communication vs formal communication

Informal- less respectful, more joking around. you do this when you are with friends or people who you know wont get insulted. Lots of slang is used.

Formal- Very respectful of others, ie. Sir, Ma'am, ect. you use this either when arguing with a superior, applying for something, like taking an interview, or when you are about to get in trouble.