User personas are fictitious replications of a prototypical user that match certain characteristics. They are usually given an alliterative name like Salesperson Sam, or Developer Dave. You can use a persona map to list out the customers key attributes, problems, and needs. Creating user personas helps a company step into the shoes of their target customers. It allows the company to experience the problems that their potential customers are having and leads them down the marketing channels where their potential customers will be looking for solutions. This then allows the company to know where and how to market their product successfully. It is not uncommon for a product to have 3-5 key personas, and to market differently to each one.