Large aperture
- Large aperture A large aperture (a wide opening) will pass a lot of light, resulting in a brighter photograph. In a dark environment – indoors, or at night – you will probably want to select a large aperture to capture as much light as possible. This is the same reason why your pupils dilate when it starts to get dark. Example - f/2.8 is larger than f/4 and much larger than f/11.
Ref - https://photographylife.com/what-is-aperture-in-photography

Small aperture
- Small aperture A Small aperture (a small opening) will pass a small amount of light, resulting in a darker photograph. A small aperture making a photo darker. a small aperture results in a small amount of background blur, which is typically ideal for some types of photography such as landscape and architecture. Example - an aperture of f/16 is smaller than f/4.
Ref - https://photographylife.com/what-is-aperture-in-photography

Aperture uses for Depth of Field
- Aperture Affects Depth of Field a large aperture results in a large amount of both foreground and background blur. This is often desirable for portraits, or general photos of objects where you want to isolate the subject. Sometimes you can frame your subject with foreground objects, which will also look blurred relative to the subject a small aperture results in a small amount of background blur, which is typically ideal for some types of photography such as landscape and architecture. In the landscape photo, use a small aperture to ensure that both my foreground and background were as sharp as possible from front to back Quick Note: The way the foreground and the background out-of-focus highlights are rendered by the lens in the above example is often referred to as “bokeh“. Although bokeh is the property of a lens, one can yield shallow depth of field with most lenses when using a large aperture and close camera to subject distance.
Ref - https://photographylife.com/what-is-aperture-in-photography