This tab allows to compare text definition of database objects or text column values:
Vertical toolbar between two panels contains additional tab-specific actions:
The state of Show tab and space characters and Show line number toggles is common for the Text diff tab and other tabs having bottom text preview (Object list, etc.).
Main text area highlights new and changed lines (whole line highlighted), bottom panel shows selected line with per-character changes highlighted. Top panel shows text changes summary: total number of rows, new, changed, new+changed and unchanged line counts. Note that when you change text comparison options like ignore case or white spaces - changes highlight and new/changed totals can be changed because of different text comparison rules.
You can filter text lines to show only new, changed or new+changed lines. In this case most of the unchanged lines are collapsed and can be shown/hidden using the +/- buttons to the left of the text area. Number of unchanged lines shown by default is configured in ADD.LINES field in the right-top corner.