The term SharePoint is used to refer to both Microsoft SharePoint Foundation 2010 and Microsoft SharePoint Server 2010 (and all the previous versions), which can lead to some confusion as to exactly what features you're going to get with your license. To make things even more confusing, Microsoft SharePoint Server comes in both a Standard and an Enterprise edition.
There are some spreadsheets which have been produced which list the features and web parts and state which version of SharePoint they're in, but sometimes you just need a consise summary.
Microsoft's SharePoint website has an edition comparison. This lists the features and feature sets that you get in each of the three editions. You can see a short summary of what each feature set entails by hovering over that item.