The privilege to enter the premises for a certain purpose is referred to as a (n) ?

License

Explanation:

The word license comes from the Latin noun licentia which means freedom, liberty. A license is usually created when a person is granted the privilege to use or enter premises without becoming authorized to complete possession of them. Premises refers to the property such as a house. It is a permission to do an act, which without such permission will result in a trespass. For example to allow a person to walk across your lawn which, if it were not for the license would be considered a trespass. License is a right pr privilege to enter the property for a specific purpose, that does not grant or confer the licensee any ownership, interest, or estate in such premises.