Updating your Apple computer is just as important as updating your Windows computer.
This can be done automatically , unlike Windows computers which may not do all updates and requires you to go in and check. (3rd week of every month is what I recommend)
On your Mac open up System Preferences and go to the App Store tab.
Put the ticks in the boxes and the updates will be done for you.
It will still pay you to go in and check every so often.
Here is a support article with further information from Apple: Updating OS X