What are the differences of these concepts? What I am sure is that all intend to enhance students' competencies. But are there differences? Is practicum be considered as service-learning? In what ways?
Internships are focused on job training and career networking (applied learning) while service-learning is concentrated on applying classroom learning in a non-profit environment to promote community needs. See,e.g,
Service learning is more like volunteering and less formal than internship and the like. However, the literature indicates that service learning can be more effective for some learners.
There are lots of concepts hanging around: Clinical Placement, Field Placement, Co-operative Education. In Sweden we use Education accommodated to Workplaces (Verksamhetsförlagd utbildning). An introduction: https://www.bher.ca/sites/default/files/documents/2020-08/BHER-Academica-report-supplement.pdf