An absolute right is a legally enforceable privilege that one has in order to take a certain action, or to not take that action. Absolute rights are commonly given in contracts or by owning property, etc. Absolute rights are distinguished from other types of rights where one party cannot make decisions or actions independently, but instead must get approval from another party.
Whether or not a right is absolute can have significant legal implications. For example, if one person has the absolute right to a piece of property, he or she can decide whether or not he or she would like to lease that land to a solar panel company for a solar farm. However, if that property has more than one owner, then both parties may have to be in agreement as to whether or not they would like to lease the property.