Claim Based Security explained in real simple way

Check this article if you are trying to understand claims based security
http://msdn.microsoft.com/en-us/library/ff359108.aspx

Office Web Apps and SharePoint Services(Excel, Word, Powerpoint Services)

I always get queries from peers and clients on difference between SharePoint 2010 and Office Web Apps. They are completely different component. Office Products have tight integration with SharePoint using the Office Web Apps feature installed in SharePoint.

Note : You can run Office Webs Apps using Office Web Apps server even if you do not have SharePoint in your organization.

Useful Links:

Office Web Apps:
http://technet.microsoft.com/en-us/library/jj219456.aspx


Office Web App Server Planning:
http://technet.microsoft.com/en-us/library/jj219435.aspx

Office Web Apps Deployment :
http://technet.microsoft.com/en-us/office/ee815687.aspx

Office Web Apps platform comparison
http://technet.microsoft.com/library/ff925944(office.14).aspx

Excel Services vs Excel Web App
http://blogs.technet.com/b/tothesharepoint/archive/2010/07/21/excel-services-and-excel-web-apps-common-different-features.aspx

Licensing
http://office.microsoft.com/en-us/buy/microsoft-office-volume-licensing-suites-comparison-office-FX101825637.aspx