When it comes to cats, most prefer to be able to go outdoors; However, allowing your cat to freely roam the neighborhood is never a good idea. There are plenty of dangers out there including moving cars, other animals, toxic chemicals, ticks, and more. It is just not a wise idea to do this. Would you allow your dog to free roam? Of course not! So what options do you have?
Leash/lead training is an option. Not all cats enjoy this and it can be difficult to train an older cat to be okay walking on a leash. It is doable with patience and time but not many people have the patience for something like this. Fenced in yards work great under supervision but it only takes one second of turning your back and your cat can very well be gone. They have a habit of finding their way around fences, even tall ones. There are also small netted tents that can be great for kittens and small cats but they can easily be broken out of and also require constant supervision too.
The only option left is an outdoor enclosure. You can use ones that are designed for dogs (with tops) or you can be more creative and go for a catio! The main difference in an outdoor dog run or kennel and a catio is that the enclosure is made specifically with your cat in mind. There are businesses popping up all over that will actually come to your home and build one for you. There are also kits that can be found at hardware stores that work great for cats but tend to be marketed for rabbits and chickens. I find the best way to have a catio is to either pay someone to come out and build one or to build one yourself!