When you first start XLIFF Translator, you’re presented with a series of text boxes.

When you create or open a project, the XLIFF Translator window will have three areas:
This is a list of the XLIFF files in your project. Click on one of the file names to open that file in the segment view. To show or hide the file view, from the menu, select View >> File List.

This pane shows information about the currently open project and file. You can drag the top edge of this panel and and down to enlarge or shrink it (or hide it alltogether).
This pane shows the segments in the XLIFF file. Here is where you will do the actual translation work.
There are two modes: Translation Mode and Review Mode. Translation Mode provides a more streamlined interface, where you can concentrate on the text to be translated. Review Mode shows the segments in a table, with the source segments in the left column, the target segments in the middle column, and a note field in the right column.