A skilled worker is any worker who has special skill, training, knowledge which they can then apply to their work. A skilled worker may have attended a college, university or technical school. Alternatively, a skilled worker may have learned their skills on the job. These skills often lead to better outcomes economically. The definition of a skilled worker has seen change throughout the 20th century largely due to the industrial impact of the Great Depression and World War II. Further changes in globalisation have seen this definition shift further in Western Countries, with many jobs moving from manufacturing based sectors to more advanced technical and service based roles. Examples of university educated skilled labor include engineers, scientists, doctors and teachers, while examples of vocationally educated workers include crane operators, CDL truck drivers, machinist, drafters, plumbers, craftsmen, cooks and accountants.