Photograph

A photograph captures a real scene, person or object, like the rocky ground shown here. Because it is real, a photo tells people "this exists and looks like this".
That makes photos ideal when accuracy matters: products in a shop, places on a travel site, people in a news story. They can also set a mood and help people feel something about a brand.
Pro tip: choose photos that show what people need to see, not just what looks nice. A clear product photo helps shoppers decide; a moody but vague one does not.