Your Security page now shows the recent activity on your account. Every sign-in, wherever it happened — not only in this browser — with the date and time, the kind of device, the country and the address it came from. Failed attempts and password resets are listed too, so you can tell an ordinary week from one that needs looking at.
There is a Sign out everywhere button beside it. It ends every other signed-in device on your account and leaves you signed in where you are, which is what you want if you have lost a laptop or think somebody else has your password. If your account has been temporarily locked after repeated failed attempts, the page now says so and offers to clear it, instead of leaving you wondering why your password stopped working.
Two-step verification has also been added to the list of protections at the top of the page, so you can see at a glance whether it is on. Nothing about how you sign in has changed, and you do not need to do anything.