Services and Items

I'm new to SAP, we run an ISP I'm trying to input a list of services/products, but i notice that SAP manages items not services or products. although on the invoice i have the option to post for a service but there is no list related to it I suppose my question would be, for a service oriented business what alternative do I have in Item Management? should I use the same item management for my services/products?

thank you