An intern or stagiaire is one who works in a temporary position with an emphasis on on-the-job training rather than merely employment, making it similar to an apprenticeship. Interns are usually college or university students, but they can also be high school students or post graduate adults seeking skills for a new career. Student internships provide opportunities for students to gain experience in their field, determine if they have an interest in a particular career, create a network of contacts, or gain school credit. Internships provide the employers with cheap or free labor for (typically) low-level tasks (stereotypically including fetching coffee for the office), and also the prospect of interns' returning to the company after completing their education and requiring little or no training.

An internship may be either paid, unpaid or partially paid (in the form of a stipend). Paid internships are most common in the medical, architecture science, engineering, law, business (especially accounting and finance), technology and advertising fields. Internships in non-profit organization such as charities and think tanks are often unpaid, volunteer positions. Internships may be part-time or full-time; typically they are part-time during the university year and full-time in the summer, and they typically last 6-12 weeks, but can be shorter or longer. The act of job shadowing may also constitute as interning.

Internship positions are available from businesses, government departments, non-profit groups and organizations. Due to strict labor laws, European internships are mostly unpaid, although they are still popular among non-Europeans in order to gain international exposure on one's résumé and for foreign language improvement.

Types of internships

An intern type means doing internship in an organization or in specific subject of study. Internships exist in various industries and settings. Here are two primary types of internships that exist in the United States.

1. Work experience internship: Most often this will be in the second or third year of the school period. The placement can be from 2 months to sometimes even one full school year. During this period the student is supposed to use the things he/she has learned in school and put it in practice. This way the student gets work experience in their field of study. The gained experience will be helpful to finish up the last year of the study.
2. Research internship (graduation) or dissertation internship: This is mostly done by students who are in their last year. With this kind of internship a student does research for a particular company. The company can have something that they feel like they need to improve, or the student can choose a topic within the company themselves. The results of the research study will be put in a report and often will have to be presented.

The practice of a mid-career person taking an internship (see Returnship) is relatively new to the U.S. but becoming more common due to the current economic crisis.