'Superpower' and Great Power are terms which easily coexist. As a shorthand, (not necessarily the only one) a superpower is a nation who's influence will be felt any place on Earth barring those it is excluded from by another superpower. A Great Power on the other hand is a nation which has an inalienable 'seat at the table' in a given strategic system i.e. its interests cannot be ignored. The US/USSR are the only two superpowers to have ever existed, China is not there yet and even though it will soon (10-20 years) outmuscle the US in East Asia the relevant quality is global reach. An example of 'Great Power' under this definition would be a nation like modern Japan. Japan is no superpower, and is dwarfed by China and the US. Nevertheless in any major crisis in the East Asian strategic system Japan is impossible to ignore or sideline*. Other nations however can be ignored, if it is in the interests of the Great/Super powers. A country like Vietnam, for instance, is no slouch but conceivably could be sold down the river if it suited all the major players to do so.
*Obviously there is one way; defeat them in a war. This is of course knocking them down a peg from Great Power status to whatever you want to call the next rung.