The difference is what you've set, lol.
The "Export File" isn't there by default, you probably added it yourself using "Add destination". The point is that you can create different export presets you might use for quick access, and name them as you want. For example one in 720p h.264, one in 4K prores....
Making a Prores file won't make your video better, however it will not further degrade it like h.264 will. You'd use it for example if you wanted to further edit the video in another program without losing quality between one and the other.