Voice overs are generally voices laid over something like music for a TV or radio commercial, movie trailers, public service announcements and so on. In jingle terms I use voice overs for idents, commercials and even in the lead up on sung jingles. A debate rages on about voice over... is it one word or two?
I did some research: http://www.musicradiocreative.com/jingles/is-voice-over-one-word-or-two/
VoiceOver is a screen reader for Apple devices and voice over IP can be used to make calls on your broadband which makes the issue even more confusing!
How would you define a voice over? Share your thoughts in the comments!