Motivation (noun)

1. A reason or reasons for acting or behaving in a particular way.
2. The general desire or willingness of someone to do something.

Origin:

Late middle english (denoting the action of moving): from old french, from latin motivus, from movere "to move".

Examples:

1. Her motivation for running the marathon was to raise money for charity.
2. Lack of motivation is one of the major causes of failure.
3. His motivation for studying hard was to get into a good university.
4. The motivation behind the project is to help the local community.
5. The company's new policy has been a major motivation for many employees to find new jobs.