iPod Touch iOS 5 Computability for 8 GB 2nd and 3rd Gen

If you have an 8 GB iPod Touch and can't install iOS 5, you may think it's a 3rd Generation. But your wrong. All 8GB iPod touches from 2008 - 2010 are 2nd Gens. They never made 8GB 3rd Gens. It's only 32 and 64's.