And larger format cameras and view cameras often have f64 or f128.

The bigger the f number, the smaller the aperture opening, which means the more parallel the light entering the camera is. The more parallel the light, the longer the "depth of field", which means that the foreground and the background will both be in focus.

When you see a portrait with the background out of focus, this usually indicates a "wide open" aperture (low f number), resulting in a "shallow" depth of field.

The disadvantage of a big f-number (small opening)? You need more light since the cross-sectional area of the opening is smaller.