The Software Product is the licenseable entity, so Adobe Acrobat 8 and Adobe Acrobat 9 are different Software Products. For examples of what Symantec see as Software Products, go to Manage > Software Catalog > Managed Software products (select to show pre defined porducts if you are on SP2 to 7.1) and look at a few of the pre defined ones.
The Software Release is the deliverable containing a package (if required) and install command line. So Adobe Acrobat 8.1 and Adobe Acrobat 8.2 would be two separate Software Releases but both would be included in the Adobe Acrobat 8 Software Product.
For more ideas on creating Sofware Releases and Software Products see:
www.symantec.com/connect/node/2489781