On September 12, 2006, as a work-in-progress called “iTV” and using a modified Front Row interface using the Apple Remote, first Apple TV was unveiled. Pre-orders for Apple TV is started on January 9, 2007. To keep it in line with the rest of their “i”-based products (iMac, iPod, etc.), it’s named “iTV”. But was not used because television broadcaster ITV holds the rights to the name in the UK and threatened to take legal action against Apple.
Apple TV started shipping on March 21, 2007 with a 40 GB hard disk. Apple released a 160 GB model on May 31, 2007 and ceased selling the 40 GB version from September 14, 2009.
On January 15, 2008, a major (and free) software upgrade was announced, that turned the Apple TV into a stand-alone device that no longer required a computer running iTunes on Mac OS X or Windows to stream or sync content to it, and making most of the Apple TV’s hard disk redundant. The update allowed the device to rent and purchase content directly from iTunes Store, as well as download podcasts and stream photos from MobileMe (.Mac at the time) and Flickr.
On July 10, 2008, Apple released the iTunes Remote app on the App Store, and the Apple TV 2.1 software update that added recognition for the iPhone and iPod Touch as remote control devices intended as a software alternative to the Apple Remote. Later updates to the Apple TV, iTunes and Remote software added support for the iPad, and introduced support for new features as they were added to iTunes.
The second generation Apple TV was unveiled on September 1, 2010. The device was now housed in a very small all-black case, about 1/4 size from the original. The new model did away with an internal hard drive and had an internal 8 GB flash storage, enough local storage for buffering purposes. All media was now streamed, instead of synced. The new device could also stream rented content from iTunes and video from computers or iOS devices via AirPlay. All content is drawn from online or locally connected sources.
In July 2011, Apple discontinued the Front Row interface. In the March 7, 2012 presentation that mainly dealt with the third generation iPad, Apple CEO Tim Cook announced a third version of the Apple TV. The new type is externally identical to the second generation model and includes a single-core A5 processor. It also supports 1080p content from iTunes and Netflix. On January 28, 2013, Apple released a third generation “Rev A” which included component changes.
source : wikipedia