Press Shift + Command + 5
Choose Record Entire Screen or Record Selected Portion
Click Record
To stop, click the Stop icon in the menu bar or press Command + Control + Esc
Find the recording on your desktop or in the location you selected
Use QuickTime Player if needed
Open QuickTime Player
Click File
Click New Screen Recording
Click the Record button
Select the screen area or entire screen
Click Stop to finish
Save the recording when prompted