Items come in various forms and will be invaluable in your journey. They can do anything from heal you to unlock a door. Items are divided into 3 categories:
As the name suggests Permanent Items never run out and are either have infinite charges or constantly provide something. Usable Items such as a health potion have a limited number of charges, it can be anything from 1 to anything less than infinity.
Special Items are ones that do not fit into either of the other categories and are deemed "special".