categories of labour

"Skilled": A tradesman, someone who has expert knowledge in a particular field that requires problem solving, for example an Electrician, Machinist, Toolmaker, etc.

"Semi-skilled" is usually a machine operator, where work is routine and well defined and "skill" is acquired by a short training period, following a set of instructions, or repetitIous work.

"Unskilled" an employee who performs menial jobs, for example a janitor, or common laborer .

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