Press Windows key + L
Press Ctrl + Alt + Del, then select Lock
Close the laptop lid if it is set to lock on lid close
Use the Start menu power options and choose Lock
On Mac, press Control + Command + Q
On Mac, click the Apple menu and choose Lock Screen
On Mac, set Hot Corners or a keyboard shortcut for locking
On Linux, use the system menu and choose Lock
On Linux, press Super + L if supported
Set your laptop to require a password after sleep or screen lock