A column in a grid is what is referred to as a field. It allows you to organize the details relevant to each record into a structured list. 

Every field has a unique field type that determines what information can be entered in it, like attachments, rating, multi-select, currency, etc. You can pick your field type from the variety of field types available to make your data rich and powerful.

You can add as many fields as you need, delete or modify as per your requirement.