Medium-format cameras are used extensively in studio photo sessions. They are also used by professionals for weddings, commercial photography, portraits, and similar types of shoots. One of their main advantages is the fact that they produce a larger negative than a 35mm system does. The larger negative enables darkroom technicians to perfect a picture so that it is nearly flawless. Since 35mm negatives are smaller, they are harder to work with in a darkroom.
Enlargements lose some sharpness when they are made.
There is often some confusion over various photo formats. If you're feeling a little uneasy in your understanding of what all this format stuff means, relax. Let me put the facts into plain English for you. A medium-format camera is one where the photographer normally looks down into a viewfinder on the top of the camera. This type of camera is also called a roll-film camera.