The Compare Files tool can be used to compare files or XML file
fragments. To compare two files side by side, open the Diff Files
dialog from . Using the 
browse drop-down list, open a file in the left side of the dialog, and the file you want to
compare it to in the right side. To highlight the differences between the two files, click the
Perform File Differencing
button. The line numbers on each side help you to quickly identify the locations of the
differences.
To compare XML file fragments, you need to copy and paste the fragments you want to compare
into each side, without selecting a file. If a file is already selected, you need to close it,
using the 
Close
(Ctrl+W (Command+W on OS
X)) button, before pasting the fragments.
You can edit both the source and the target file. The differences are refreshed when you save the modified document.
The Compare Files Window
Adjacent changes are grouped into blocks of changes. This layout allows you to easily identify and focus on a group of related changes.
When you select a change, a widget containing actions that can be used to copy or append
changes from either of the two sides is displayed:
Append left change to right and
Append right change to left- Copies the content of the selected change from one side and appends it on the other, after the content of the corresponding change. As a result, the side that the arrows point to will contain the changes from both sides.
Copy change from left to right and
Copy change from right to left- Replaces the content of a change from one side, with the content of the corresponding change from the other side.
