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, 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, though mostly unpaid, are popular among non-Europeans to gain international exposure on one's resume 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 that 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.

Fee-based internship programs

An intern type can be an internship in a organization or in specific subject of study. Some companies will find and place students in internships for a fee. What is included in fee-based programs vary by company. Overall, the advantages are that they provide internship placement at a reputable company, provide controlled housing in a new city, mentorship and support throughout the summer, networking, weekend activities in some programs, academic credit and other benefits. Disadvantages to fee-based programs include the restriction of internship opportunities to wealthy students who can afford paying thousands of dollars to work for little or no wages, while at the same time improving their chances of professional work after graduation.