Hey Shanks,

A computer appliance is a computer with software or firmware that is specifically designed to provide a specific computing resource. Such devices became known as appliances because of the similarity in role or management to a home appliance, which are generally closed and sealed, and are not serviceable by the user or owner.

check out below links

https://community.servicenow.com/community?id=community_question&sys_id=29068761db1cdbc01dcaf3231f96...

Computer [cmdb_ci_computer] is the table for client Appliance types.

Please find below thread for detail understanding:-

https://community.servicenow.com/community?id=community_question&sys_id=97505a91db4533c05129a851ca96... 

ServiceNow has a lot of documentation on this, look through this for additional help:

https://docs.servicenow.com/bundle/london-servicenow-platform/page/product/configuration-management/...

CMDB model categories are associated to a CI class and are part of the Asset Management module.  check this article out:

https://docs.servicenow.com/bundle/london-it-service-management/page/product/product-catalog/concept...

https://community.servicenow.com/community?id=community_question&sys_id=fd529761db101fc01dcaf3231f96...

https://community.servicenow.com/community?id=community_question&sys_id=11f781891b218c907a5933f2cd4b...

kindly mark Correct and Helpful if applicable.

Regards,

Indrajit.