The magnification of a microscopic image is usually indicated in one of two ways:
By stating the final magnification in the image legend. This indicates, numerically, how many times larger the image is than the original object.
By using a scale bar. A small bar is placed on the image, and its length represents a known distance. You can use it as a reference to estimate the size of structures in the image. Observe the scale bar in the figure.
On this site, we use a simplified way of describing magnification: small, medium, and large. We consider these categories sufficient for its educational purposes.
More detailed information about magnification is available in the Technical Data section, that can be accessed through the main menu at the top of each page.
Liver. Staining: hematoxylin and eosin. Medium magnification.