Create better images instantly by using a histogram

a histogram is a graph representation of pixels in an image. the left side represents blacks or shadows, the right represents the highlights and the middle is the mid-tones. an image is exposed fully when the graph is filled from one edge to the other. when there are gaps on the image it shows there youre missing important information. you can shift the exposure to cover all the tones. using tools that camera's provide you and photoshop you can adjust the exposure.