Write an essay on Theories and Concepts in Leadership and Management. It needs to be at least 250 words.A leader nurse takes responsibility and guides the staff in accordance to the nurse ethics. A nurse leader identifies the strength of other staff members and utilizes to create an effective model (Kelly, 2012).Management on the other hand is an elective or appointed position. A manager works based on goals set by an entity, a successful manager is one who performs according to expectation (Kelly, 2012). Management in this case is authoritative. Consultations are done on a horizontal basis. A manager defers form a leader in the manner in which decisions is arrived at. A manager works with an aim of improving the quality and output while leader works on the negatives and work on them to ensure an appropriate working environment is created (Marquis & Huston, 2014).In some cases the two functions may overlap. In this case an authoritative manager may have the traits that qualify him as a leader. The manager works with the available staff while leaders work on their negative and motivate them towards better performance. He ensures the external and internal environments are functional and are effective to ensure quality performance (AANAC, 2013). In this case policy making and execution are enjoined as a single function. This would imply that the two functions overlap. An effective nurse should aim at ensuring the overlap created by these two functions is harmonized and effective system