What specific part of the iPhone's camera helps it capture more light to take better photos when it's very dark?

The iPhone's camera uses several specific integrated parts and processes to capture more light and take better photos in very dark conditions. The two primary physical components directly responsible for gathering light are the camera sensor and the lens's aperture. The camera sensor is the light-sensitive chip that converts light into electrical signals. A larger sensor, typically found in the main wide camera, can collect more photons, which are individual particles of light, because it has a greater surface area and often larger individual pixels to absorb them. The lens's aperture is the adjustable opening that lets light pass through to the sensor. A wider aperture, indicated by a smaller f-number (for example, f/1.5 compared to f/2.2), allows more light to reach the sen....