An update usually means making small changes or fixes to a computer, like fixing a few bugs.

An upgrade means installing a completely new version of an operating system.

So, updates tweak things a bit, while upgrades give you a whole new version.

1. Click on the Apple in the corner of your screen, choose System Settings. Click General in the sidebar of the window that opens, then click Software Update on the right
   
   
2. To Upgrade your computer click on Upgrade Now
   Note: This requires an administrator password. Contact SMPH Shared Services IT Helpdesk if you need assistance.
   
   
   
   
3. To Update your computer click on More Info...