Imagine you're sat in a space surrounded by a wall that has a bunch of doors in it. Each door, when open, will allow a different type of vehicle to come through it. Door 22 allows cars to come through, door 80 allows buses to come through, door 79 allows bicycles to come through. If you want cars to be able to enter your space you open door 22. If you don't want cars to be able to enter your space you keep door 22 closed. It's like that. Except the space is your operating system and all the services it runs, the wall is the operating system's firewall and the doors are ports.
There are no spoons involved in this analogy.