Here you can find sufficient info about cam sex.
As you can understand from the words cam sex, its a type of virtual sex which you can get using your laptop or computer camera, or one of your smartphone.
Skype sex is a cam sex, but the cam sex doesn't limit with skype only. There are hundreds of so called sex cams in internet, which means that these sites show web cam girls broadcasting in real time live.
Very frequent thing about cam sex is c2c or cam to cam which means you have a private session with web cam model during which she watches you and you watch her.
Also by cam sex its possible to call guys masturbation while they watch cam model doing a sexy show online.
Cam sex doesn't have a very long story, it started his life in about 2000 year, that time there was very little concurrence in the niche and cam girls earned a lot. So it is today but with much more efforts then earlier.
I can give as an example such fact. In 2014 when I started working as a cam model on chaturbate there were only 7 pages containing web cam working girls, guys and couples, about 50 performers on each page, in 2019 there are already 29 pages with web cam models, so you can understand that cam sex now is much more popular then it was earlier.