The row in datagrid is called DataGridItem and in gridview is called GridViewRow. They are all inherits TableRow Class. DataRow is only one kind of row in GridView control. There are many other types of rows such as Footer, Header and Pager. Here is a link for details: http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridviewrow.aspx
GridView can be created by DataSet or DataReader. It can be selected in DataSourceMode in DataSource controls such as SqlDataSource, or you can bind it by yourself.