The countries in Europe are packed into a relatively small continent. To make it easier for citizens and visitors to travel freely across borders, 26 European countries have come together under the Schengen Agreement. Some countries (such as the U.S.) dont require a visa to visit these countries, while others do require a visa.
If youre a traveler from a country that does require a visa for the Schengen Area, the Schengen visa is the only one youll need to travel within all these countries. Youll need to purchase travel insurance, as you'll be required to show proof of insurance.
Even if you dont need a Schengen visa to travel around Europe, its still a great idea to purchase a policy so that you have health insurance coverage on your travels in case of any accident or illness.