SLR refers to “single-lens reflex. Single-lens means the image can easily be seen through the lens of the camera. And reflex means it can be seen through a mirror. SLR contains films on which the images are recorded, and later on, these can be developed for creating reality. SLR film can only record a limited number of images at one time, and for further images, you have to change to film roll. SLR cameras have modern bodies with two-tone colors. These cameras also have more buttons but do not contain any monitor.