What does resolution refer to in an image?

Resolution in the context of an image specifically refers to the number of pixels that make up the image. It is typically expressed in terms of width and height, such as 1920x1080, indicating how many pixels are present horizontally and vertically. Higher resolution means more pixels are used to create the image, which usually results in greater detail and clarity. This is because more pixels can capture finer details and allow for smoother transitions of colors and shapes.

While other choices mention aspects related to images, they do not accurately define resolution. For instance, the number of different colors used pertains more to color depth than resolution itself, while clarity of an image can be influenced by resolution but is not synonymous with it. Similarly, the format of the image file (like JPEG, PNG, etc.) relates to how the image is stored or compressed rather than its resolution.