Data types and field properties format data in database tables. Data types define the type of data in a field, such as number or text. Field properties define how the data is formatted, like limiting text fields to a certain number of characters. Setting the proper data types and field properties allows data to be sorted, searched, and used in calculations correctly. Common data types include text, number, date/time, and currency. Field properties include field size, format, and input masks to control how data is entered.