Students get an opportunity to witness the life-size of plant, equipment, tools, accessories, etc. that they have seen only on the books. It also provides them an opportunity to see the working conditions, facilities, work culture, etc. As far the industry is concerned, it helps them to attract recruits to their organization. It's a win-win for the industry and the institution, if managed appropriately.
Educational tour is partly to let the students experience the freedom as well as realize the challenges on being on their own. It helps to build camaraderie among students and develop healthy relationship with the faculty. It also helps them to combine a purposeful visit to an industry with some sight-seeing and relaxing time. The most important learning from the tour is self-management, team work, leadership, problem solving, decision making and communication.
Internship is a form exercise where a group of students are deputed to an organization to work and learn simultaneously for a fixed period of time, generally short-term. It is a challenge to get organizations to accept interns and so it's somewhat beyond the influence of the institution. Very students get this opportunity.