Why were there inns in the Middle Ages?

Inns were originally planned by the Romans and survived the fall of the Empire. The purpose was to provide food, drink and lodge to the travelers of the time and a place to rest horses if somebody had one. The inns were frequent as the distance between two inns was the maximum that a person could travel in one day or closer.

Later in the Middle Ages the network of inns had the protection of the Kights of the Temple

In the middle ages, people traveled and not many were rich enough to have a horse or carriage. They walked, and when they got there they paid with whatever money they had for a meal and a room, or the full journey was to long for the rich people to make.