The size of capacitors are continually becoming physically smaller as the dielectrics improve in them.
Your question is probably in reference to different manufacturers capacitors.
There are applications where a manufacturer needs a short, fat capacitor to fit in the
chassis properly, or a tall, skinny capacitor to fit in some other physical application.
Electrically, they're the same. The physical differences are due to manufacturer spec-
ifications that they believe fit some industry need.