Construction workers on site normally fall into three categories: Skilled, semi-skilled, and unskilled workers. The skilled workers, or tradespeople, are employees who have training in specific areas of construction like plumbing, electrical, concrete, and carpentry work. The semi-skilled workers often referred to as apprentices, work alongside the skilled workers to learn a specific trade and provide a helping hand. The unskilled workers, or laborers, perform a lot of the grunt work on a job site. These workers do tasks such as keeping the site clean and moving equipment and supplies to where the skilled workers have easy access to the materials they need to perform their jobs.