Trades differ in the level of education needed to start. Sometimes, as a power line installer and repairer, the trade can start with a high school diploma. People are then instructed in the trade while they begin practical work. These are apprenticeships that can take as little as two years until one is fully equipped in the trade. Other trades, such as cardiovascular technicians, mostly need either an associate’s degree or certification. A trade may also mandate a bachelor’s degree, such as in web development or construction management.