Some owners keep their cat inside, some are able to go outside. Those outside cats are free to come go out whenever they want, they still have a home and owner. If we leave our cat outside depends on the situation, culture and laws. In the most European countries house cats are free to go where they want. But in some countries that freedom is limited by a law that determines that cats should stay within a certain radius. This is also in Germany and Denmark, where the cats are allowed to leave the house for 150 meter, but if they pass that 150 meter and they make too much noise, then they can be killed. In the United States, especially breeders don’t let their cats outside, because they find it too dangerous. In Australia and New-Zealand cats aren’t allowed to go outside, to protect rare species.
Outside cats use the fences/walls in their own garden to mark out their territory. If your cat gets outside he usually looks for places he’s been before and left his mark. Those places are often created by humans and can be high things, like a fence, from where they can oversee their territory.
The size of their territory depends on their gender and if they are fixed or not. Non-fixed female cats have a territory the size of 3 backyards. When they are fixed they are happy with just one. A non-fixed male cat has a territory the size of 7 backyards, but when they are fixed it reduces to 3.
The territory of an outside cat is used to rest and to hunt, even though outside cats usually hunt for their own entertainment and not because they are hungry. If cats share a home, they most likely share their territory as well.
When a cat is fixed, this can be a little handicap for the outside cat who meets stray cats. Stray cats that live in the neighborhood see outside cats as a threat for their own territory, their food sources and sexual status. That’s why outside cats are sometimes attacked by stray cats.