The second difference Nayar indicates that managers have circles of power while leaders have circles of influence (2013). Leaders work through inspiration and that is wonderful, but it is also true that not all people will respond to all leaders. A manager must be able to exert control over people that goes outside of the leadership arena. Without the possibility of consequences, some people would not function. Even if a manager's only control is the ability to determine whether or not a person is an appropriate fit for a team, that level of control can be outcome-determinative. A leader could divert more resources to leading a recalcitrant team member than would be a prudent use of team resources.

The final difference that Nayar indicates is that leaders lead people while managers manage work (2013). One of the things that is imperative to keep in mind is that, in most workplace scenarios, management is about achieving goals. As a result, a manager must play an administrative function. In addition to handling job goals, managers often have to oversee...

Leaders may be more people-focused, but it is important to realize that this people-focus may not always meet all of a business's needs. Moreover, it is critical for managers and leaders to work together. For example, a good manager not only makes sure that a team member is meeting quotas and deadlines, but also listens to employee feedback about innovation and directs those reporting to him to the leaders who handle innovation.
References

Murray, a. (2014). What is the difference between management and leadership? Retrieved

April 16, 2014 from Wall Street Journal website: http://guides.wsj.com/management/developing-a-leadership-style/what-is-the-difference-between-management-and-leadership/

Nayar, V. (2013, August 2). Three differences between managers and leaders. Retrieved April

16, 2014 from Harvard Business Review website: http://blogs.hbr.org/2013/08/tests-of-a-leadership-transiti/