Aperture control doesn’t automatically make photos “better” — it lets you choose the look you want.

The main reason to choose aperture is depth of field: a wider aperture (smaller f-number) gives less of the scene in focus, while a narrower aperture (larger f-number) keeps more in focus. Aperture choice is also part of the tradeoff with shutter speed, since changing aperture makes the camera adjust shutter speed to keep exposure consistent.

A good way to learn is to switch to Aperture Priority mode and practice with static subjects. Put the camera on a tripod, keep the framing the same, and shoot the same subject at several apertures. Then compare the results so the only changing variables are aperture and the matching shutter speed.

Do this with different subject distances and with each lens, so you learn both the depth-of-field effect and how each lens behaves at different apertures. Once you know what your lenses look like wide open versus stopped down, you can pre-visualize the result and choose the aperture intentionally rather than letting Program mode decide.