A part-time position held during the school year or summer months where the student receives practical training in a field usually related to their course of study. At times, internships may serve as a preamble or precursor to professional employment. Some internships place the student under close supervision by a mentor in an apprentice-like position. Some internship programs provide stipends, although this is not always the case.
Check out StudentAdvisor.com's Guide to Internships.