This dialog is used to configure the file comparison feature and to start comparing files.
First file, second file
Select the first and the second files to compare. All currently opened documents as well as last recently used documents are listed in the drop-down. In addition, you can enter the full path manually, or use the ... button to browse for it. After pressing the browse button, select one or two files. If you select a single file, it is used either as a first file, or second file. If you select two files, they will be used as first file and second file correspondingly.