Cyber sex means any sexy chat, pictures or films that are exchanged by email, instant message or social networking sites like Facebook or a chat room.
Cyber sex may seem safer than real sex in some ways, because there is no risk of sexually transmitted infections or unplanned pregnancy.
However there are still risks involved and, as with any type of sexual activity, it is never ok for someone to coerce (pressure) you into anything sexual you don't want.
For much of the time it may seem no big deal, and many people enjoy cyber sex without any problems.
But it's worth thinking about what the risks might be.