If you hunt with only a 30/06 and a 7mm/08 you can be well served(in most normal scenarios) by standard bullets. Premium style bullets of various constructions can give you a huge edge when you are pushing the limits of...the size of the game you are after, the bodily construction of the game you are after, the distances you are shooting, and the velocities you are shooting. That said, there are many other reasons to use premium grade bullets...even if they are of a standard construction. Consistency of quality is a big one.
A standard soft-type mushrooming bullet (cor-lokt and their ilk) would take care of average sized whitetail at average distances at average velocities......but hunters sometimes find themsleves outside those parameters and that is why the premium bullets have a market. I'd suggest that you start by logging on to the websites of as many bullet manufactures as you can...and read their own descriptions and summaaries of their different bullet lines and their uses. It is actually way too involved to be described in a singel post-answer here.
Sierra, Hornady, Winchester, Remington all make a variety of bullets for various stated uses...then Nosler, Swift, Barnes..just to name a few of the "other" makers.