Service Pack 3 para Microsoft Office 2007 is a package that contains absolutely all the patches that have been released for any of the Microsoft Office 2007 programs or their previous Service Packs.
A patch is a solution to a detected problem. Do not see it as a pegote but as a vaccine to a problem, the fact is that when problems accumulate and are necessary several patches are usually presented in the form of a service pack, which contain all the patches and install them properly.
Well, this service pack is cumulative, that is, it contains everything related to previous patches or updates. When you run it, it will install only what is necessary.