at the same time. Its the same as a right click.
https://support.apple.com/en-us/HT204895
Super handy--forgive the pun
Use Multi-Touch gestures on your Mac
With a Multi-Touch trackpad or Magic Mouse, you can tap, swipe, pinch, or spread one or more fingers to perform useful actions.
Trackpad gestures
For more information about these gestures, choose Apple menu ? > System Preferences, then click Trackpad. You can turn a gesture off, change the type of gesture, and learn which gestures work with your Mac.
Trackpad gestures require a Magic Trackpad or built-in Multi-Touch trackpad. If your trackpad supports Force Touch, you can also Force click and get haptic feedback.