Most websites are built with more than one document.
Translation Assistant lets you translate each document at a time. To move between one document to the other, use the document selector at the top of the editor window.
The selector shows how many documents are in the website, and which one is currently open in the editor. Click on the document name to see a list of all documents:
This list also shows the translation status of each document.
Note that in this example both documents are fully translated.