Apprenticeship is a system of training

Training

The term training refers to the acquisition of knowledge, skills, and competencies as a result of the teaching of vocational or practical skills and knowledge that relate to specific useful competencies. It forms the core of apprenticeships and provides the backbone of content at institutes of...

 a new generation of practitioners of a skill. Apprentices (or in early modern usage "prentices") or protégés build their career

Career

Career is defined by the Oxford English Dictionary as a person's "course or progress through life ". It is usually considered to pertain to remunerative work ....

s from apprenticeships. Most of their training is done while working for an employer who helps the apprentices learn their trade, in exchange for their continuing labour for an agreed period after they become skilled. Theoretical education may also be involved, informally via the workplace and/or by attending vocational school

Vocational school

A vocational school , providing vocational education, is a school in which students are taught the skills needed to perform a particular job...

s while still being paid by the employer.
The system of apprenticeship first developed in the later Middle Ages

Middle Ages

The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

 and came to be supervised by craft guild

Guild

A guild is an association of craftsmen in a particular trade. The earliest types of guild were formed as confraternities of workers. They were organized in a manner something between a trade union, a cartel, and a secret society...

s and town governments.