A period during which the seller agrees not to negotiate with other buyers, usually granted on signing an LOI.
In a sale
Exclusivity is the point where negotiating leverage turns. Before it, several buyers compete; after it, one buyer has the diligence period, the purchase agreement, and time on its side. Every term that matters is best settled before exclusivity is signed, and the period itself is a term worth negotiating.
Where it comes up
The Go-To-Market Analysis (GTMA) builds the file a buyer would build on your business, before a buyer does.