There are multiple kinds of film for instant cameras, depending on the model. Fujifilm uses Instax film for their instant cameras. It has various film, such as Instax Mini, Instax Square, and Instax Wide.
Polaroid, which is the most popular instant camera at this time, also has various film, such as Polaroid I-Type (which can’t be used in vintage Polaroid instant cameras), Polaroid Go, Polaroid 600, and Polaroid Zink 2x3. Just make sure that you use a film that is compatible with your instant camera.