There are many definitions of leadership. At its core, leadership is the action of influencing a group of people, in a team or an organisation.
Leadership uses social influence in order to enable others to maximise their efforts in achieving organisational goals.
There are many leadership styles, adapted to the needs of the situation, the business and the employee.
Some of the more commonly used terms here are situational leadership, agile leadership, value-oriented leadership, transformational leadership, task-oriented and relationship-oriented, to name just a few.