What’s the difference between an update and an upgrade?
An update is software, usually downloaded from the Internet for no charge, that corrects problems or improves an application or the Mac OS X. Security Updates are especially important because they protect your Mac from bad code or malicious intent. Don’t always select “Later” when prompted by your Mac to install an update. Installing updates usually take just a few minutes. Staying current will keep your Mac running well.
An upgrade can be software or hardware. An upgrade is replacing an application, computer or one of its components with a newer version that offers an improvement on the existing version. Software upgrades often include a version number. Most Mac computers last long enough to be eligible for a software upgrade in their lifetime.
It is important not to get more than two revisions behind with the Mac OS X. The current version is 10.9. If you are running Mac OS X 10.6 or earlier, you probably already know it’s time to upgrade. Many of the features that Mac a great platform, such as iCloud, won’t work with the older OS.
Some OS upgrades are minor and offer fewer new features. These are generally considered a maintenance upgrade, such as from 10.8 to 10.9. However, some OS upgrades are very disruptive and require new versions of applications or hardware, such as 10.6 to 10.7. Verify what versions of hardware and software are required before installing any upgrades or buying new hardware.
And always backup before an upgrade.