What is the difference between a DataSource and DataAdapter?

What is the differe开发者_运维百科nce between a DataSource and DataAdapter? I'm trying to decide if I should descend from IDataSource or IDataAdapter for code to be shared between Winforms and WebForms and I can't seem to figure out what the difference is other than slightly different ways to use them.

---

DataSource is just source of data from where we are populating the data i.e. DataSet, DataBase, XML File, etc...

DataAdapter is tool or class using by which we can populate/update data from database.