They types of activity that qualify a user as "Active" are outlined in the "Categorization of active members" chart in "Members" tab of Workplace Analytics.
There are 3 types of Active members based on this chart:
In your examples both users are considered active.
- User 1 (views content only, but does not comment or contribute) is a Consumer
- User 2 (view content, comment but do not author content on pages/channels) is a Contributor.
Please let me know if you have any questions,