Lead or manage?

Lead or Manage? When you lead, do you manage? When you manage, are you leading? Some say leaders lead people, managers manage tasks. However, can't leaders manage people and managers lead task? Playing on the semantics? Perhaps.....until now, I do not have an answer. Human Beings are complicated beings. Alone as a single entity, we have our own idiosyncrasies. Take this and add another human being with his/her set of idiosyncrasies, the picture gets complicated. Add more individuals to the picture...