Linq for Confusion

time to read 2 min | 245 words

Can someone please make sense of the following statement? (Found here, on the LINQ Chat log):

Q:What is the key difference between ADO.NET Entities and LINQ 2 SQL?
A: LINQ to SQL is an ORM over your relational database schema plus some mappings. LINQ to Entities is an ORM over a conceptual object-less model (ERM) that is a mapping over your relational database schema.


Q: Is there still an effort to integrate LINQ to SQL and LINQ to Entities?
A: There is an effort on going to align these products, but not to integrate them together.

Can someone please explain me the business sense behind the decision to push two (and let us not forget Linq For DataSet, which I haven't heard about lately) competing frameworks that does the same thing? Can anyone come up with a good explanation for the use cases where I would want to use one and where I would want to use the other?

This has a positioning conflict written all over it.