There are three key changes being made to the social network:
The website switches from a three-column format to two-columns letting the main news feed take up more space. This allows all posts - whether they are friends' updates or adverts - to take up a bigger proportion of the web browser with more prominence given to images and video rather than text describing a link.
A pop-out black bar is added to the left-hand side of the page. This contains app bookmarks, links to specific friends, the chat and calendar tools, and the live updates ticker.
In addition to the standard news feed, users can select other alternative feeds. These include one which shows all the updates posted by friends rather than just the ones selected by Facebook's algorithms; one dedicated to organisations and people the user "follows"; a page featuring only posted photos; and a music-themed feed containing updates from artists the user likes, concert announcements and details of songs their friends are listening to through services including Spotify and Rdio.