Are these two notions distinct, synonymous or complementary? Many views prevail in the literature.
I find the views of John Kotter and Peter Northouse particularly compelling, based on my own experience with leaders and managers at all levels of organizations, especially during times of change.
Kotter argues that leadership and management involve two distinct but complementary sets of action. Leadership is about coping with change while management is about coping with complexity. Here is a summary* that I keep handy to distinguish between the two.
* From Peter G. Northouse’s Leadership: Theory and Practice, Fourth Edition (2007) in which he draws from John Kotter’s A Force for Change: How Leadership Differs from Management, (1990).