Why do students need to travel to other countries?

For many reasons. What they want to learn may only be or best be available in other countries. For example, they may want to learn a foreign language, which is best done in a country that speaks that language. Students travel as part of foreign exchange programmes. Part of the courses they do may require doing activities in other countries. Students travel to volunteer their services, purely voluntarily or as part of their studies.

Outside of their studies, a lot of students like to travel. They are usually young and free, and it is a good time of life to see a bit of the world, before they settle down into life with jobs and families. Students travel to get work in other countries. So for all of these reasons, and many more, students travel to other countries.