In DealSignal, a persona represents a detailed profile that includes the professional characteristics of an ideal contact: job position, job function and seniority, experience, skills, location, and more. Also in DealSignal, you could include company criteria, that is important for contacts that fit the persona.
With personas, it is easier to apply required filters in searches and discoveries. DealSignal could also compare potential contacts to your persona by applying the Persona Fit Scoring and provide you with lists of Look-a-like contacts.