An apprenticeship is a system of training a new generation of practitioners of a trade or profession with on-the-job training and often some accompanying study (classroom work and reading). Apprenticeship also enables practitioners to gain a license to practice in a regulated profession. Most of their training is done while working for an employer who helps the apprentices learn their trade or profession, in exchange for their continued labor for an agreed period after they have achieved measurable competencies. Apprenticeships typically last 3 to 6 years. People who successfully complete an apprenticeship reach the "journeyman" or professional certification level of competence.
Although the formal boundaries and terminology of the apprentice/journeyman/master system often do not extend outside of guilds and trade unions, the concept of on-the-job training leading to competence over a period of years is found in any field of skilled labor.
In early modern usage, the clipped form prentice was common.
The system of apprenticeship first developed in the later Middle Ages and came to be supervised by craft guilds and town governments. A master craftsman was entitled to employ young people as an inexpensive form of labour in exchange for providing food, lodging and formal training in the craft. Most apprentices were males, but female apprentices were found in crafts such as seamstress,tailor, cordwainer, baker and stationer. Apprentices usually began at ten to fifteen years of age, and would live in the master craftsman's household. Most apprentices aspired to becoming master craftsmen themselves on completion of their contract (usually a term of seven years), but some would spend time as a journeyman and a significant proportion would never acquire their own workshop.