Leadership

the process of directing the behavior of the others toward the accomplishments of some objectives.

Leader Vs Manager

Managing consist of
rational assessment of a situation and systematic selection goals and purposes,
systematic development of strategics to achieve these goals,
the marshalling of the required resources,
the rational design,
organization, direction and control of the activities required to attain the selected purposes and
finally the motivating and rewarding of people to do the work.

Leader is

one of the influencing function, subset of management.
mainly behavioral issues.

A manager make sure that a job gets done and
leader cares about and focuses on the people who do the job.