How might an inventory of activities be different from an inventory of objects? *(I don’t understand this question. )*

I inferred you are referring to a business case, not computer and technology.

Explanation:

Put simply, an inventory of activities involves a record of the business routine activites such as last maintainance, last purchase of supplies etc.

However, the inventory of objects is diffrent as it records specifically how much inventory (objects; goods) a business have on hand.