There are many ways to sign in. The simple way is to use a pen and paper. For example, teachers in schools ask students to sign their names and count the number of people.

There are many ways to sign in electronically, and punching in at work is another form of sign-in to prove a day's work.

Some websites and forums have sign-in areas, and 3 1 conference network proves that you have been to the forum 1, which increases the number of forum clicks.