Assignments make activities available to users. When you create an assignment, you identify an activity (not event) to be assigned to users, when it is to be available to those users, and which users are to have access to it.
You can create as many or as few assignments as you need.
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Note: Pricing, registration options, or certifications requirements are not enforced when an activity with those attributes is assigned. (For example, even if the activity has an associated price, users who are assigned that activity will get it for free.)