Open QuickTime Player
Click File
Select New Movie Recording
Click the red Record button
Choose your camera and microphone if needed
Click the Stop button when finished
Save the video file
Open Photo Booth
Click the Record Video button
Click the red button to start recording
Click it again to stop
Save or share the video
Open Screenshot toolbar with Shift + Command + 5
Select Record Entire Screen or Record Selected Portion
Click Record
Click the Stop button in the menu bar when finished
Use a third-party screen recording app if needed
Open the app
Select video or screen recording mode
Start recording
Stop and save the video