What is the difference between "==" and "~="?

I know that == goes for if statements Not much else I know about == I know Nothing about ~= though And I need to know the difference Please This would be helpful.

"==" means if a value it's equal to something a function will run for example "if Workspace.You == nil then -- nil means 0/nothing print("player does not exist") end" and "~=" means if a value it's not equal to something then a function will run for example "if Workspace.You ~= nil then print("Player Exist") end"