Difference inline and code behind

Inline code written along side the html in a page. Code behind is code written in a seperate file and referenced by the aspx page.

Difference Between Varchar And NVarchar

The difference between the two is that Nvarchar is used to store uNicode data, which is used to store multilingual data in your database tables. Other languages like chinese have an extended set of character codes that needs to be saved and this datatype allows for this extension.

If your database will not be storing multilingual data you should use the varchar datatype instead of nvarchar datatype. Because nvarchar takes twice as much space as varchar.