Sharepoint is the server side of things with Expression Web being the web page design software.
Also note that Shrepoint comes in two flavours - the more or less free extremely cut-down version or the feature rich, everyone is raving about it, enterprise version which is anything but free.
I would doubt what you have is a free version of Expression Web - as that is an £80 upgrade, £120 - £130 full price product, so unlikely to be given away with anything.