How do f-number and aperture size relate?

F-number and aperture size work together to control how much light enters your camera, like a door controlling how much people can come in.

Think of the f-number as the size of the door. A smaller f-number, like 1.8, means a bigger door, more light comes in. A bigger f-number, like 5.6, is like a smaller door, less light comes in.

The aperture size is the actual opening that lets the light through, it’s like the doorway itself. When you use a small f-number, your camera opens up to a larger aperture, letting more light inside. When you use a bigger f-number, your camera uses a smaller aperture, and less light comes in.

It's like having a big, open door for a party (more people come in) or a small door for a quiet meeting (fewer people come in). The size of the door (f-number) and how wide it is (aperture) are closely connected, both help decide how much light gets into your camera.