If you own an Nvidia graphics card, GFE governs the use of a number of features, including in-game video recording, Shield streaming, Battery Boost, and game optimizations.
The company is making several new changes to the application today, and announcing a major change to how it distributes driver updates that could have far-reaching implications. First, the updates. Starting immediately, Nvidia's GameStream technology will allow users to stream titles in 4K at 60 FPS, with support for 5.1 audio, if your hardware can handle that output level in the first place. You'll need a Shield TV to receive a 4K stream from a local PC, and Nvidia recommends a wired connection for best performance. The other new feature introduced today is the ability to broadcast to YouTube Live, the streaming giant's new service meant to compete with Twitch. GeForce Experience can manage both logins and stream to either service.
By far the biggest announcement today is a fundamental change to how Nvidia distributes its driver updates. One of the differences between Teams Red and Green is that Nvidia has often been faster off the block when it comes to Day 1 support for features like SLI. While DirectX 12 is expected to help level this difference, since it moves support for multi-GPU configurations to the developer (and allows for fewer driver-side optimizations in general), early driver support for DX11 remains important. Up until now, those game-ready drivers have been available to anyone with a GeForce card. Going forward, that's going to change.
In the future, only GeForce owners who both install GeForce Experience and register the service by providing Nvidia with an email address will have access to Game-Ready driver downloads, which will be pushed exclusively through GFE. That doesn't mean you won't be able to download a driver from Nvidia.com - it just means that the drivers on the website will be updated periodically, not on a per-release basis.