Trades are composed of jobs in which workers typically train for the work through apprenticeships. The training period may last from two to five years. Skilled workers such as carpenters, plumbers, electricians, and mechanics learn how to do the work through apprenticeships and on-the-job training. Many also start out as helpers.

The apprenticeship system dates back to medieval times, when guilds for skilled crafts workers were formed in Western Europe. Master craftsmen controlled these guilds and supervised the workers, production methods, and the quality of the products. Apprentices trained for up to seven years before they became full guild members.

In the 1600s and 1700s, skilled crafts workers emigrated from England to America to work as apprentices. They entered into a contract with a master craftsman. The terms were usually that they would work for free in exchange for training in the craft and room and board. Masters usually provided apprentices with education in reading, writing, and arithmetic. Apprentices may also have received clothing and/or a set of tools. Some were paid at the end of the apprenticeship. Apprentices were predominantly young men, sometimes as young as 14 years old. Apprentices worked alongside the master and journeymen, who had completed apprenticeships and were paid workers. The types of trades apprentices learned in colonial America were blacksmith, bookbinder, brickmaker, cabinetmaker, carpenter and joiner, cooper, gunsmith, printer and bookbinder, among many others.

The national apprenticeship system was established in 1937 with the Fitzgerald Act, which gave the U.S. Secretary of Labor authority over apprenticeship programs, established an apprenticeship office within the U.S. Department of Labor, and enabled state agencies to register and administer apprenticeship programs. Apprenticeship, as described by the Department of Labor, “is a highly desirable form of training for workers because it is first and fo...