OS X Service Packs?

Solution 1:

Whoever wrote the requirements probably is more familiar with Windows terminology. While they aren't called "service packs", every major release of OS X (such as 10.6, 10.7, and 10.8) has had multiple "minor" or "point" releases containing improvements and fixes. See this list for details of release dates. For the example given, 10.6.8, 10.7.5, and 10.8.5 would be the most-current releases of the major versions mentioned.

These minor updates have historically been made available through the Software Update item under OS X's Apple menu, and, since either 10.7 or 10.8, are now available through the Mac App Store.

Solution 2:

Service Pack is Microsoft naming convention for a major update pack which incorporates a plethora of minor security and other updates in one single installer.

A rough Apple equivalent are the latest Combo Updates:

Mac OS X 10.6.8 Client Combo Update
Mac OS X 10.7.5 Client Combo Update
Mac OS X 10.8.5 Client Combo Update