Intern
An intern is someone on a fixed placement at a firm rather than in a permanent job. The word covers spring weeks, summer internships, off-cycle internships and placement years, which differ a great deal in length and in how much real work they involve.
Interns are expected to learn quickly rather than to arrive knowing the job. The team watches how you work, how you take feedback and how carefully you check what you produce, because the main point of most internships is to decide who to offer a permanent job.
When a posting says intern, look at the programme it names to see how long it runs and whether it can lead to an offer. Each programme has its own page on Learn.