Why is it that all managers are leaders but not all leaders are managers?

Managers are leaders - Pastence (appointed by themselves)

Leaders are not managers - presentence (appointed by others)

This is absolutely true, anyone can be a manager but it takes a certain type of individual to be a leader. A great quote I read once states "leaders plan the journey and sell the tickets, managers drive the bus to the destination". In other Words, managers carry out work FOR someone else whereas leaders will be creative, have a vision and bring others along with their vision.

I have written a couple of articles on leadership versus management and they are listed below this answer.