There are two or more options on this tab depending on which screen you are on:
Field information from a specific record in your database
This option starts a visual wizard that allows you to choose a table from your database, then a specific record/row from your table and then which field/column name to choose.
Manually enter an SQL statement
This is for advanced users, such as programmers and IT Professionals, who have a good understanding of SQL (Structured Query Language). SQL is very powerful and allows summarising information from databases.