Work is effort directed to produce or accomplish something. It may be done for oneself or for others. If for others, it is usually done in exchange for payment, though may also be freely volunteered, as for charitable causes.
After the educational phase of their life is complete, most people in the industrialized world spend most of their lives working in exchange for payment. Unfortunately, a substantial percentage of people do not enjoy their work, and find it essentially without intrinsic meaning. This is a significant social problem.