There are various free screen recorders available for Mac but most of them don't allow you to record webcam video along with screen recording and editing annotations.QuickTime Player, Monosnap, Icecream Screen Recorder (Free Version) and Jing are the best in free offerings as they features so many customization and editing option with annotations. But if you are going to do a professional video recording for business presentation and Tutorials then go for Snagit or Comtasia. I found this article on

best screen recorder for Mac- http://www.hawkdive.com/2017/08/8-best-screen-recorder-for-mac.html

which has put all the best and free recorder together very nicely with pictures and YouTube video.