dumb question?
The intake manifold is the actual aluminum part that sits just under your throttlebody. I looks like a beer keg cut in half. The phrase "intake plenum" is a term used by most to describe the same thing, but others often use it to describe the belly pan (the plate on the bottom of the manifold) or even the gasket (i.e. they say their plenum needs fixed, they really mean the gasket between the intake plenum and the belly pan needs fixed).
But, to get technical, plenum actually only refers to the space inside the intake manifold, the space that gets filled with air.
But, to get technical, plenum actually only refers to the space inside the intake manifold, the space that gets filled with air.



