Exclusivity
A restriction on working with competitors, or on reusing the work (priced separately).
Exclusivity is a client buying something they don't receive: your ability to do similar work elsewhere, or your right to show and reuse what you made.
It comes in two flavours that get confused. Category exclusivity stops you working with the client's competitors for a period. Asset exclusivity stops the footage appearing anywhere but the client's channels (including, if drafted carelessly, your own portfolio).
Both have real cost, and both should be scoped and priced. Category exclusivity removes a slice of your addressable market for its duration; an unbounded version of it is a serious commitment sold as a clause. Asset exclusivity that catches your portfolio removes your ability to win the next job with this one. Always carve out portfolio use explicitly.
Where this comes up
The four axes that define what a client may do with your work, why they're priced separately from production, and the carve-out to never sign away.
The nine clauses that prevent almost every freelance dispute, why a deposit is a commitment test, and what to do when a client won't sign anything.
Buyers aren't judging your best work. They're reducing risk on one specific job. Build for that and the same reel starts converting.