SPF artillery vs mortars, what’s the difference?

I have yet to try the SPF artillery but having played with mortars for a bit they seemed to be almost the same ..?

I don’t know what the kill radius of the SPF shell is, but the one from mortars was quite small, and didn’t seem to do much unless you hit someone with 10 meters, mortars were also able to shoot fairly far, reaching almost any position on the map or at least that was my experience, so what’s the difference other then range and mobility?