While photo and model release forms are often used interchangeably in the photography world, technically, there are some differences between the two contracts.
A model release form effectively gives ownership of an image to the photographer. That is, a subject provides permission to the photographer to use the photos for whatever they want.
A photo release form gives ownership to the client. So if a photographer takes professional photos of you, by default, the photographer owns those images, and you need permission from them to use it.
To summarise, a model release form benefits the subject, and a photo release form benefits the photographer. But, commonly, these terms are used to describe both situations.