A permission set is a reusable collection of settings and permissions that gives users extra functional access without changing the one profile already assigned to them. Salesforce recommends managing that access with permission sets and permission set groups rather than creating a new profile for every job or extra task, so profiles stay limited to default settings and people receive only the permissions their work requires. Use a permission set instead of a new profile when the need is object, field, user, or other functional access; create or clone a profile only when users need different defaults that permission sets cannot own.