Leadership is about influence
Leadership can simply be defined as the ability to influence others. Leadership is the work that is done by the leader. It is a process of social influence in which one person can enlist the aid and support of others in the accomplishment of a common task.

In the course of his survey of leadership theories and research; Stogdill came across innumerable definitions of leadership.
For our purpose, we may define leadership as the process of directing and influencing people so that they will strive willingly and enthusiastically towards the achievement of group objectives.
Keith Devis said that leadership is the process of encouraging and helping others to work enthusiastically toward objectives.
According to Koontz and Donnell, the act of leadership is the process of influencing people so that they will strive willingly and enthusiastically toward the achievement of the group goal.
Ideally, people should be encouraged to develop not only a willingness to work but also a willingness to work with confidence and zeal. Confidence reflects the experience and technical expertise; zeal is earnestness, and intensity in the execution of work.
A leader acts to help a group achieve objectives through the exploitation of its maximum capabilities.
A leader does not stand behind a group to push and prod; she/he places herself/himself before the group, facilitates progress and inspires the group to accomplish organizational goals.
Leadership is the potential to influence the behavior of others.
It is also defined as the capacity to influence a group towards the realization of a goal. Leaders are required to develop a future vision and to motivate the organizational members to achieve the visions.
Leadership is both a process and a property.
As a process -focusing on what leaders do; leadership is the use of no coercive influence to shape the group or organizational goals, motive behavior towards the achievement of those goals and help define a group or organizational culture.
As property leadership is the set of characteristics attributed to individuals who are perceived to be leaders.