I strongly recommend that you configure your Mac to require a password when it is awoken from sleep or screen saver. It’ll take a minute or two to setup this feature and it’ll slow down a thief if your Mac ever gets stolen.

Apple added this feature many, many years ago, I’m confident that it was at least 10 years ago so you can enable this with macOS version 10.6 and higher. To enable this feature, do this:

1. Click on the Apple menu in the upper left corner of your Mac’s screen and select System Preferences.
2. Click on the icon for Security & Privacy
3. Click the General button.
4. Insert a checkmark next to Require Password…after sleep or screen saver begins. You might need to click the padlock icon in the lower left corner to unlock this window so it can be edited. After clicking the padlock icon, type in your administrative username and password.
5. Click on the pop-up menu to select how quickly you want the password to be required after sleep or screen saver begins. I recommend picking immediately, 5 seconds or, at most, 1 minute.

You’ll now be required to type your password, at times, through the day, when you return to using your Mac. I think this mild inconvenience is worth the added security you get from having this feature enabled.

Apple also provides instructions for enabling this feature.

To truly protect the contents of your Mac, consider enabling FileVault, which is a security feature that encrypts all files on your Mac.