

The most common example of external audio is audio input through a mic. External audio, on the other hand, comes from a sound interface connected to your system via USB, HDMI or other ports. Audio generated by any running programs comes under the definition of internal audio. The difference between Internal and External audio is easy to understand: Internal audio uses an audio chip built into your motherboard. This is a serious problem for most people trying to record their screens since it is impossible to make engaging content without any audio. QuickTime doesn't capture audio playing on your Macbook's internal audio card: for example, it won't record the sound coming from programs like games or music interfaces. However, QuickTime comes with a set of challenges, the most severe being that it doesn't capture internal audio.

It's common knowledge that Apple offers a built-in screen recorder, QuickTime Player. Differences Between Internal Audio and External Audio
