Guided Math is sometimes used as the title for the entire math block time. I find this confusing! I like the term Balanced Numeracy for the whole program- which consists of whole class teaching, stations and small group instruction. Add a warm-up and a closure activity and you have a balanced math block!
Guided Math is similar to Guided Reading- it is the time when you pull small groups based on skill or level. You teach the same skill you are teaching all of the kids on that day, but you teach it on their level!