Aperture & Depth of field also focal length

Aperture is a small adjustment hole that is in the lens which lets light in the camera. its size for aperture are different sizes of aperture from lens to lens. When you large your aperture you get a small focal length your picture is going to be more focused on your object than the background and the closer the object is the better the focus , when you get a large aperture and a large focal length you get a small focus on your object so that means majority of your picture will be blurry.