Samsung's official website
Samsung is a large Korean multinational company which spans industries such as television sets, shipbuilding, semiconductors (like memory and processors), in addition to phones and tablets. Samsung is the largest Android device manufacturer worldwide, though they’re also the primary support of another mobile operating system, Tizen, and previously invested in an OS called Bada.
Samsung is the largest Android device developer worldwide
Samsung was founded in 1938 as a trading company, and didn't get into electronics until the late 60s. Oh-Hyun Kwon is the CEO of Samsung Electronics. Samsung's first Android smartphone was the Galaxy, released in 2009, and their first Android tablet was the Galaxy Tab was announced in 2010.
Traditionally, Samsung's Android user interface has been something called TouchWiz, which included a wide array of Samsung-made apps and customizations. For example, there are fitness tools, note-taking apps, news readers, multi-window viewing, and lots more.
Samsung has had to go through a number of patent litigations with Apple, and was found by California court to be infringing on some Apple patents in 2012. These include technologies for voice search, slide-to-unlock, data synchronization, and others.