What you are describing is university work placement, or workplace experience/practice.
An apprenticeship is a full-time job (1-4 years) with lower pay to learn how to do a job. Usually, an apprenticeship is only offered to school leavers (instituto) to learn a trade/skill/craft, or long term unemployed who need to start a new career.
An internship is also full-time, but is unpaid. Usually lawyers in the US or UK will take an unpaid internship (1-2 years) so that they can work with the best professionals in their field, and they hope that when they finish the internship they will then be offered a fantastic job somewhere else because they had that experience.