An internship is a period of work experience offered by an organization for a limited period of time. Once confined to medical graduates, internship is used practice for a wide range of placements in businesses, non-profit organizations and government agencies. They are typically undertaken by students and graduates looking to gain relevant skills and experience in a particular field. Employers benefit from these placements because they often recruit employees from their best interns, who have known capabilities, thus saving time and money in the long run. Internships are usually arranged by third-party organizations that recruit interns on behalf of industry groups. Rules vary from country to country about when interns should be regarded as employees. The system can be open to exploitation by unscrupulous employers.

Internships for professional careers are similar in some ways. Similar to internships, apprenticeships transition students from vocational school into the workforce. The lack of standardization and oversight leaves the term "internship" open to broad interpretation. Interns may be high school students, college and university students, or post-graduate adults. These positions may be paid or unpaid and are temporary. Many large corporations, particularly investment banks, have "insights" programs that serve as a pre-internship event numbering a day to a week, either in person or virtually.

Typically, an internship consists of an exchange of services for experience between the intern and the organization. Internships are used to determine whether the intern still has an interest in that field after the real-life experience. In addition, an internship can be used to build a professional network that can assist with letters of recommendation or lead to future employment opportunities. The benefit of bringing an intern into full-time employment is that they are already familiar with the company, therefore needing little to no training. Internships provide current college students with the ability to participate in a field of their choice to receive hands-on learning about a particular future career, preparing them for full-time work following graduation.