Employees have many motivations and desires that keep them moving each day. Each has within them something that pushes them to accomplish tasks within their lives. Sometimes these motivations are simply money while at other times they could be something more. Knowing what motivates an employee can make the difference between an average and a steller performer.
Consider what an organization would be like if it was full of highly motivated and energetic employees. It would be great, people would get things done, and the organization would be zooming along. The problem is that this is fantasy land and doesn't truly happen in real life.
People hide their motivations, don't believe they can accomplish them and then bury them with layers of other issues. They are difficult to detect and understand. However, with time and with a watchful eye it is possible to start picking out patterns of how people act on issues.
For example, someone who is motivated to move up the ranks within an organization will generally take on new projects, jump in front of the line, be super excited about getting recognition. A person seeking more freedom and independence will want projects they are in charge of, don't want much interaction with their boss, and will seek to set their own course.
It takes time to determine what your employees want. It is possible to do this when you watch what they are doing, where they emphasis their skills, and how they act and react to situations. Once you have found the basic motivations you can then allocate assignments and work in a way that furthers the organizations needs and raises the employees satisfaction.