Various similar categories of items are grouped in the system to form an Item Class. Item Class is defined in Item Class Setup screen.
For Example:
You can define various item classes like, Hardware Item Class, Event Class, General Merchandise Item Class, Miscellaneous Item Class etc.
Hardware Item Class may contain items like Decoder, Integrated Receiver Decoder, Smart Card, Cable Modem, Router, Switch, Set-Top-Box, Digital Video Receiver etc.
Event Class may contain movies, sports events, concerts etc.