This is the first common photography term you should learn. Simply put, aperture is the size of the opening in the lens. Think of the lens as a window—large windows let in more light, while small windows let in less light. A wide open aperture will let more light into the image for a brighter photo, while a smaller aperture lets in less light. Aperture is measured in f-stops; a small f-stop like f/1.8 is a wide opening, a large f-stop like f/22 is a very narrow one. Aperture is one of three camera settings that determine an image’s exposure, or how light or dark it is. Aperture also affects how much of the image is in focus—wide apertures result in that creamy, unfocused background while narrow apertures keep more of the image sharp.
