Thanks, I looked those over.
I think my confusion is that if you read those two pages, they are basically saying the same things.
ie:
What is a case?
It's helpful to think of a case as an interaction between your company and another entity. Basically speaking, creating a case means creating a record of interaction between a representative and a new or existing contact, lead, or vendor. These interactions can include phone calls, meetings, and other activity types - from service appointments to follow-ups. Cases can also document an interaction with one of your own employees, which is helpful when you are internally tracking employee performance, vacation time, and a host of other potential scenarios.
What is an activity?
One of the cornerstones of CRM is the ability to keep track of every interaction and task your business takes part in, including interactions with customers, leads, vendors, partners and your own employees. These interactions are collectively called activities, and can include (but are not limited to): meetings phone calls emails other appointments
If you see the parts italicized and underlines, they seem to be saying the exact same thing except that activies can track a few more things than cases?