Katie is very excited because she has just learnt how to button her own shirt. this ability to remember how to button her shirt is part memory

This ability to remember how to button her shirt is part of procedural memory.
Procedural memory belongs to your long-term memory, meaning that if you learn it once, you will probably know how to do it for a very long time (if not for the rest of your life). The name itself implies that you learn certain procedures, such as buttoning your shirt, or riding a bike, or writing.