Sexting

Sexting is the act of sending sexually suggestive electronic messages, mainly between mobile phones. The term became popular during the early 21st century. The term is a portmanteau of "sex" and "texting".
The term was first used in print in 2005 in Australia. A naked picture that you make of yourself is sometimes called a nelfie, a mix of the words naked and selfie.
If adults exchange such pictures, this is not a problem. The problem starts when children do this: The image of a teenager or child with little clothes may be child pornography. Many countries have laws against child pornography. This usually includes penalties for owning or spreading such images.