Differences between SP versions in BO

Dear experts

I am a little bit confused with how it work the support package in BO.

I understand that a SP is a set of fixed issues but I don't know if a SP brings new features to the solution.

For example, if I have BI 4.1 SP5 and I upgrade it  to SP7, besides of fixing issues,  what other advantages do I have with this SP?

Are the the features  if I upgrade from BI 4.1 to 4.2?

I appreciate any comments,

Regards

DanielO