@mcc Really, apt is just a wrapper that forwards some things to apt-get and some things to apt-cache. The vast majority of the time, all it does is save you from typing that "-get" or "-cache"
As long as your hands are willing to type those few extra characters, there's no difference. It's just there because people ask "why do I have to remember which commands are in apt-get and which are in apt-cache" and "why do I have to type that extra -get and -cache"?