I've read through the documentation but I still don't understand what the purpose of Items would be in my small environment.

I'm part of a support group consisting of 2 members who will be handling Incidents and Generic Requests.

I understand categories and types but Items are just ID numbers that are completely foreign to a "customer" who is trying to create an Incident Request. Why would you have a "customer" choose from a list of Item ID numbers when they have no idea what Item the ID number is associated with? Why have an ID number instead of just a title like categories or types?