@Esssie31 It was most likely a stray, because (a) it wasn't spayed/neutered, (b) it was very shy, and (c) we know it doesn't belong to the only people with a permanent residence nearby.
Here in Greece, it is very common to provide stray cats with food and water. And because everybody knows that, people whose house cats are on a special diet and mustn't eat certain food would never let them go outside. 🙂