1. Layout:
Obviously, the new layout will be the first thing that you notice about the new Twitter. Basically the function of this new design is to put everything together right in front of your face. In general the whole display is quite larger, and each panel seems wider.
2. Context
Now when you hover over a Tweet with your mouse an arrow will appear. When you click on it, you're right panel will display a details pane. Here, you will see @mentions, retweets, and latest tweets from any user that you click on.
3. @mentions
Adding an @mention is now easier because the "what's happening?" panel now has autocomplete, much like Facebook adopted awhile back in the search box.
4. Media
Now when you click on a user's link for a picture, it will be viewed on the right panel alongside the Tweet. In the past the link would open a whole new window in order to view the photo or video.
5. Profile
For starters your profile picture is a lot larger, and all your information details have moved to the left side. Another difference in profile is that you can now see your tweets all in a timeline with your avatar, exactly as you would see it on the homepage.
