You can use the Screenshot app or QuickTime Player to record your Mac screen with background sound and, if needed, your own voice.

If you want to record your screen on iPhone or Android, watch these videos: The easiest way to record a screen on a Mac is by using Quicktime. Quicktime comes with every Mac.

So I have a QuickTime movie. Finder getinfo on the file shows that it is a QuickTime movie, with codecs H.264 and AAC - both of which should be supported by QT. However, QT player is unable to ...