Simplifying the Histogram

[nadimpr]

Think of the histogram as a visual cheat sheet for photographing bright tones. To render a subject as true white, you want the data on the right-hand side to be as close to the edge as possible. This will indicate a crisp exposure rather than a muddy, grey appearance. As you change the exposure to let in more light, the histogram will inch towards the right. Keep adjusting your settings until it's literally just a hair from the outer wall. You are now maximizing all of the wonderful dynamic range your camera is capable of.

When you are shooting on snowy days, it's very difficult to judge an exposure purely based on the LCD screen. The histogram eliminates the guesswork and gives you a quick data-based look at the exposure.

Source: https://www.nyip.edu/photo-articles/archive/simplifying-the-histogram