These words and phrases are all common when we use the internet. Sometimes you can use them when discussing activities that do not require a computer.
Log In
Phrasal verb: To gain permission to use a computer system by providing a username and password. When you log in, the computer records your activity on the system.
Sign In
Phrasal verb: Similar to “log in,” but more commonly used outside of the computer world. May involve providing information such as your name or identity card for security purposes.
Register
Verb: To provide information about yourself for the first time in order to use a computer program or attend an event. Registration may be necessary before logging in or signing in.
Registering often involves paying money, while logging in or signing in typically doesn’t.