A checkbox field is useful for true/false values within a record. For example, a task tracking base might have a checkbox field called "Done" that you can check off when a task is complete.
When your cursor is over a checkbox cell, you can hit enter to check/uncheck it. Alternatively, you can click on the cell to check/uncheck.
Users on Airtable Pro plans can change the style of the checkbox symbol from the default green check.