SharePoint 2010 Editions – Comparison
SharePoint 2010 comes in three versions. The free version (Foundation) has so many features and may be all you need for your business. The Standard versions adds several features and capabilities to the free version and the Enterprise adds even more to both Foundation and Standard. To get the official verdict on how the three compare and contrast, check http://sharepoint.microsoft.com/en-us/buy/Pages/Editions-Comparison.aspx and make sure to mouse over features to read information briefs or even click (if enabled) to find more.
The above link may not answer very specific questions on feature availability. In such situations, you are encouraged to investigate further and one good place to start is the MS SharePoint forums which is mostly community driven: http://social.msdn.microsoft.com/Forums/en/sharepoint2010general