But you should also set a password to protect your Mac when the screensaver is active, and you can set a firmware password to prevent someone from starting up your Mac from an external drive. The best way to prevent unauthorized access to your data is to encrypt your startup drive.
This article covers five areas where you can encrypt or password protect files: Best of all, you can do this with built-in software and features that are part of macOS. To protect your sensitive data, you should use encryption and password protection wherever possible macOS provides you with a number of ways to implement it. How To How to Encrypt and Password Protect Files on Your Mac
