The fundamental concept of the aperture is that it refers to the aperture in a camera's lens that allows light to enter. The aperture is similar to the human eye. You can change the size of the opening on the lens by either making it bigger to let in more light or smaller to let in less light. This size is usually quantified in terms of 'f-stops' such as f/1.4, f/2, f/2.8, and so on. The smaller the f-stop number, the larger the aperture opening, and vice versa.
