The aperture plays a role in exposure as well as the depth of field. Alow f-number creates a larger hole in the lens, allowing more light into the camera. Higher f-numbers have the opposite effect, creating smaller holes that reduce the amount of light
Having less light available means the sensor has to be exposed for longer to record an image. This can be problematic when you’re shooting in low-light conditions, as the shutter speed (which controls the length of time the sensor is exposed) may become too slow to freeze the movement of the subject or the camera – giving you blurred results.
There are a few ways to address this. You could increase the ISO to make the camera more sensitive to light, for example. This allows you to use faster shutter speeds with smaller apertures, although picture quality gets ‘choppy’ at higher ISO sensitivities.