What is Knowledge Work in GTD?
This term, coined by Peter Drucker, refers to the kind of work that produces unique knowledge such as decisions, analysis, problem solving, theory, strategy, planning, design, art, and technology. In this kind of work, the task is not given, it has to be determined by the worker.
Part of the knowledge workers' job is to actually define their work. They have to clarify the meaning of the things they let into their world, and decide what they need to do about them.