Karaoke is a form of entertainment in which amateur singers sing along with recorded music (and/or a music video) using a microphone and public address system. The music is typically a well-known pop song minus the lead vocal. Lyrics are usually displayed on a video screen, along with a moving symbol or changing color and/or music video images, to guide the singer. In some countries, a karaoke music video with lyrics and the option to disable the original voice track is called a KTV. Due to its English pronounciation, it is sometimes incorrectly spelled "kareoke".
The concept of creating studio recordings that lack the lead vocal has been around for probably nearly as long as recording itself. Many artists, amateur and professional, perform in situations where a full band/orchestra is either logistically or financially impractical and so they use a "karaoke" recording, but they are actually the original artists. (This is not to be confused with "lip syncing" in which a performer mimes to a previously produced studio recording with the lead vocal intact.)
Karaoke is one of the most amazing ways to come together as human beings. We are truly connected when we are as vulnerable as standing on a karaoke stage. I believe it is the ultimate in community bonding.