What’s New in Windows 8.1?
Windows 8.1 is more customizable.
One of the first things you'll probably notice is that you're no longer stuck with just two tile sizes for your apps. Now you can use really small tiles for apps that you want to quickly access but which don't have live tiles that display information when the app is closed.
Or, you can have a really big tile for an app that uses a live tile to show you information such as current weather conditions, news headlines, stock market feeds. In addition, you can now customize the Lock Screen with live tiles or your favorite photos.