Which term describes an individual in an occupation that requires advanced training to gain skills and knowledge?

The term "professional" refers to an individual who has undergone extensive education and training in a specific field, allowing them to perform tasks that require a high level of expertise and skill. Professionals often adhere to industry standards and ethical practices, and they typically hold licenses or certifications that validate their qualifications. This designation encompasses a wide range of occupations, including doctors, lawyers, engineers, and educators, among others.

In contrast, workers may possess various skill levels but do not necessarily require the advanced training that professionals do. Amateurs are individuals who engage in activities for enjoyment rather than as their main profession and are not typically recognized for their expertise. Trainees are individuals who are in the process of receiving training and have not yet fully developed the skills or knowledge necessary to be considered professionals. Thus, "professional" aptly describes someone who has completed advanced training and is qualified to operate within their field.