QuickTime Player can be used for screen capture, including on screen audio by using Soundflower.
Please see the attached document in the box below for detailed instructions
More information can be found here:
http://osxdaily.com/2010/11/16/screen-recorder-mac/
If you need to listen to the sound while recording, please see the information below:
http://apple.stackexchange.com/questions/212829/how-to-record-both-screen-and-sound-with-quicktime-on-el-capitan