I think you are probably asking what the difference between linq2sql and entity framework is.
Linq and linq2sql are two different things. Linq is a language that was been created to make data querying a 1st class language construct. This means that you have powerful data query syntax built right into the language. You get full intellisense and compile time syntax checking. This is a big improvement over writing sql snippets in your database management app and then calling sproc's.
linq2sql is the first orm / object relational manager which is a data access layer designed to make it easy to query sql databases with linq syntax. there is a big story behind it but basically because Microsoft is such a big company two teams started out to create what would basically be the same thing. This was the linq2sql team and the entity framework team. When they realised they were both working to the same ends the linq2sql guys joined the ef team and the ef team adopted linq as the underlying query language.
linq2sql was ready to be released so Microsoft released it. Then ef was released and everyone basically ripped it to shreds and said it was rubbish.
linq2sql is not really going to be developed any more and the version two of ef (called ef 4 to coincide with the .net 4 release) is coming out in about march 2010 sort of timeframe. This is a major improvement and from what I have read so far answers all of the major gripes people had with v1 of ef. I am looking forward to its release.
so there you go, to summarise:
linq = language integrated query syntax
linq2sql = first orm microsoft released as an interim until ef was ready
ef 1 = generally accepted as a rubbish orm
ef 4 = going to be great
if you want actual technical details on any of these topics then just type them into google and you will find lots of tutorials...Jameschowdare, if this helps please login to Mark As Answer. | Alert Moderator