Focus: As an employee, your focus is on your own duties. As a leader, your focus must be on the work of everyone in the business (including your own).
Orientation: As an employee you are task-oriented, while a leader is primarily goal-oriented.
Accomplishing tasks: An employee gets work done directly. A leader gets work done indirectly through others.
Development: Individual employees tend concentrate on their own self-development. Leaders must develop their own skills while also developing others.
These are just a few of the ways the role of an individual contributor differs from that of a leader. Can you think of others? If so, share them in the comments.