There are 3 essential roles within the Scrum team, the product owner, the Scrum master and the development team.
The product owners are the members of the team that have the deepest understanding of their product. The PO's focus is generally oriented on the understanding of business and market requirements and using this understanding to prioritize the work the the development team needs to undertake.
PO's are not project managers, they do not actively manage the team's status. The product owner ensures that the work done by the development team brings maximum value to the business. The product owner should always be an individual, because more than one person giving guidance to a team might lead to mixed messages.