What is the longest living city in the world?

I'm curious, could you elaborate on the concept of the "longest living city in the world"? Is it referring to the city with the oldest history, the one that has been continuously inhabited for the longest period of time, or perhaps a city that has managed to preserve its original architecture and culture through the ages? I'm eager to understand the criteria used to determine such a title and which city, in your opinion, fulfills these criteria the best.