Why were there many literate, educated people in medieval cities in western Europe?

The medieval cities of many European countries were filled with literate people. This fact is due to the fact that sales and interaction with foreign representatives took place in the cities. Cities in the Middle Ages were centers of literacy and cultural life. People were literate because many had access to education and enlightenment. They had libraries, secondary schools, parish schools and other social institutions. Mainly wealthy people and artisans lived in the cities.