A user will have a collection of Site user rights which determine their level of access in that Site. Most user rights are, however, determined by the circle user rights.
The user license a user has, dictates the user rights that can be assigned to them. A user will only take up one user license for the entire Site.
The easiest and most recommended way to assign site user rights is by creating site user right groups and assigning these to them. The users will then inherit the user rights attached to that particular user right group.
Note that to get access to the Data API, the user must have Data API Read Access as part of his site user rights. Granting this additional right will incur an additional license cost per user.
