Because power operates both relationally and reciprocally, sociologists speak of the balance of power between parties to a relationship: all parties to all relationships have some power: the sociological examination of power concerns itself with discovering and describing the relative strengths: equal or unequal, stable or subject to periodic change. Sociologists usually analyse relationships in which the parties have relatively equal or nearly equal power in terms of constraint rather than of power. Thus 'power' has a connotation of unilateralism. If this were not so, then all relationships could be described in terms of 'power', and its meaning would be lost. Given that power is not innate and can be granted to others, to acquire power you must possess or control a form of power currency.