One more caveat: some apps, like Apple’s built-in DVD Player, will block you from doing any screen recording.
You can, of course, turn on the external mic and turn up the volume, but this won’t give you great audio.
For that, you’ll have to download a third-party app, like Soundflower. It also lets you record external audio - anything coming in through your mic - but the Mac’s built-in options don’t let you record internal audio. Luckily, Macs have this feature built in ( your iPhone does as well), letting you record part or all of your screen. Whether you want to save a video of what’s playing on your screen, share what you’re looking at with friends, or film a tutorial, recording your Mac’s screen can come in handy.