VoiceOver is a screen reader built into Apple Inc.'s OS X, iOS, tvOS, watchOS, and iPod operating systems. By using VoiceOver, the user can access their Macintosh or iOS device based on spoken descriptions and, in the case of the Mac, the keyboard. The feature is designed to increase accessibility for blind and low-vision users, as well as for users with dyslexia.
VoiceOver was first introduced in Mac OS X 10.4 and the target was users who had difficulty in reading due to vision impairment, particularly the blind. A preview had also been made available for Mac OS X 10.3 Panther, and was titled "Spoken Interface Preview."
VoiceOver treats the user interface as a hierarchy of elements, which are navigated by various keystrokes. Elements also are "interacted" with—for example, interacting with a text box allows reading its text and, if possible, editing it; interacting with a scroll bar allows it to be moved using the keyboard.
VoiceOver also includes support for many Braille displays for those who are both blind and deaf. In addition, VoiceOver includes features for those that cannot use the mouse, such as keyboard-based navigation.