Interpol is like a group of people who work together to help the police from different countries communicate with each other. Sometimes, people need to travel to other countries but they don't have their own passports because they lost them or they never had one. In these cases, Interpol can give them a special document called a "travel document" that allows them to travel to other countries. It's like a temporary passport that they can use until they can get their own passport. This document has some special features that help other countries know that it's a valid document, like special stamps or watermarks. It's important to have a travel document when traveling internationally because it shows that you have permission to be in the country you're going to visit.