Session is used to cache data between pages at the same Project, each new user logged has his own Session. Response.Redirect just send the browser to a new URL.

Response.Redirect() sends a redirection header to the client, and the client itself requests the new page.Session: Session is a server side object, which transfer or access data between page call.

we can use response.redirect in both html& aspx pages. but server.redirect can be used in aspx pages only but at same server