# Preview Control

The Preview Tab is used to display records from the source data before they are imported to the target.

Using this tab, you can see the results of expressions you write at steps 3 and 4 of the Profile Editor.

There are three tabs:

### Preview Control

This tab allows you to specify which record in the source to start the preview at, and how many records to display.

### Source Records

This tab shows records exactly how they are read from the source

### Modified Records

This tab shows how the source records are modified in the 'Add Fields' and 'Change Data' tabs.