Maybe you've noticed that the URL of the page changes almost everytime you do an action on the translation interface: moving from a segment to another, changing filters, searching a word, etc.
Actually the current state is kept in the URL so you can share URLs from your work with your collaborators/translators. If they follow the link, they will get right where you were: same filters, same selected segment, same target language.
Also, the navigation history is preserved so the back button of the browser will bring you back exactly where you were before. It's not much, but that's unfortunately not always like that on modern one-page applications.