Stadia is a cloud gaming service, and does not require additional computer hardware, only requiring the device to have an Internet connection and support for Google Chrome. Stadia works atop YouTube's functionality in streaming media to the user, as game streaming is seen as an extension of watching video game live streams, according to Google's Phil Harrison; the name "Stadia", plural of "stadium", is meant to reflect that it is a collection of entertainment, which the viewer can choose to sit back and watch, or take an active part in. As Google had built out a large number of data centers across the globe, the company believes that Stadia is in a better position for cloud gaming compared to past endeavours like OnLive, PlayStation Now, and Gaikai, as most players would be geographically close to a data center. Stadia supports the streaming of games in HDR at 60 frames per second with 4K resolution, and anticipates eventually reaching 120 frames per second at 8K resolution. Players can start games without having to download new content to their personal device. Players can opt to record or stream their sessions onto YouTube through Stadia. Viewers of such streams can launch the games directly from the stream with the same save state that they were just watching. While Stadia can use any HID-class USB controller, Google developed its own controller which connects via Wi-Fi directly to the Google data center in which the game is running, to reduce input latency. Google is also exploring further ways to reduce latency, using an idea called "negative latency" which involves prediction of user input through various means so that any apparent network lag between controller and game response is minimized. During its GDC 2019 keynote reveal, Google confirmed that the controller would also feature Google Assistant, which will automatically search YouTube for relevant, helpful videos related to the game they are currently playing at the touch of a key.