The number of training cycles is a concept that describes the duration and length of training. It is used to describe the number of weeks, months or years that employees or students receive training in a specific training program or course. Curriculum is a scene that describes vocational training, skills training, language training and academic courses. The length of training period can measure a person's learning progress and mastery in a specific skill or knowledge field, and can also be used to evaluate the scale and difficulty of training projects or courses.