Required Software Updates on a MacBook

To locate and install required software updates, click the Apple icon in the top left.

The Apple icon in the top left
 

From here select "System Settings".

The options available under the Apple icon
 

Then under the "General" tab, select "Software Update".

Software Update settings
 

If there are updates available, you can select to update now. For updates to a newer operating system, you can specify if the upgrade should go through now or be scheduled for later.

Selecting to update