Streaming

• Hulu uses streaming video, which means that the video file is never fully downloaded to the computer or device that's playing the video, but only the part being viewed and the upcoming portion. The future video is stored in a buffer that has a limited capacity. Streaming video allows the original file to remain with whoever is hosting it, so Hulu can serve up all sorts of videos, but no one can download them. Hulu has been granted licenses from several TV and movie networks to host their videos since the networks know that the content will only be used according to the license agreement.
  
  

Licensing

• Broadcast licenses are highly specific about what content can be broadcast where and when. In early 2011, Hulu's license only covers distribution of the network content through computers, not through mobile phones or other Internet-connected devices. Because of this, Hulu blocks any mobile phone that attempts to view videos on its site. Since mobile devices have an identifier in the Web request that points to the browser and operating system being used, Hulu is able to block traffic from mobile phones so it can remain in compliance with its license agreements.
  
  

Hulu Plus

• Because people want to watch Hulu on mobile devices, Hulu has developed a product called Hulu Plus. This is a service with a monthly fee that allows users to download a separate application to their mobile devices and watch Hulu videos. Hulu was able to negotiate a separate license agreement to cover the mobile devices. In January 2011, Hulu announced the creation of a Hulu Plus app for Android phones that would become available later in the year.
  
  

PlayOn

• PlayOn is a computer program and Android application combination that skirts the edges of the Hulu license restriction. Essentially, installing the PlayOn program on a computer allows it to stream video to an Android phone. Hulu, along with other video services, is satisfied since the content is streamed from its servers to a license-approved device. From there, PlayOn restreams the video from a computer to a mobile phone via the Internet.