Power is generally defined as “the capacity to guide others' actions toward whatever goals are meaningful to the power-holder” (Messick & Kramer, 2005, p. 277). As explained in Lussier and Achua (2010), power "is about achieving influence over others" (p. 110) and "power is the leader’s potential influence over followers" (p. 110).
Lussier, R. N. & Achua, C. F. (2010). Leadership: Theory, application, and skill development (4th ed.). Mason, OH: Cengage Learning.
Messick, D. M. & Kramer, R. M. (2005). The psychology of leadership: New perspectives and research. Mahwah, NJ: Lawrence Erlbaum Associates.