The aperture refers to the size of the opening inside the camera lens which can be adjustable and helps define the amount of light coming into the lens to hit the camera sensor. The measurement of the aperture is f-stops, and a higher number of f-stops shows that there will be less light passing through the lens. The aperture can be adjusted based on the settings of the camera for a specific image.
You often find the automatic aperture control options with entry-level digital cameras. For more high-end models, the aperture setting can be controlled manually or you can also let the camera automatically set it.
Popular Misspellings: apeture or apature