A union apprenticeship is a training program sponsored by a labor union that is designed to qualify participants for jobs as electricians, plumbers, ironworkers, and skilled labor positions. An apprenticeship mixes classroom instruction related to your duties with on-the-job training with more experienced tradesmen. As an apprentice, you must complete a standard number of hours of both to complete your program. After you complete an apprenticeship, you can work as a journey worker in your field, which means you can take on more responsibilities, work without supervision or with minimal supervision, and contract on your own.