<p>What is the differences between those 2 assuming I'm using SQL Server as my database? Are they the same?</p>

Long answer: google.
Short answer: using entity framework, you will be able to create something based on classes (partial, that you can "extend") resembling domain objects (not true DDD though, that's why NHibernate still exists and linq to nhibernate is being developed), using sql you will be just thinking database and tables.