What is the importance of PostBackUrl property of a button?

Answer:

By default every webform sumbits to itself,but if the PostBackUrl property of a button is set to the url of another page ,then the form is posted to that url instead of itself.

<asp:Button ID="btnCrossPagePostback" runat="server" PostBackUrl="~/Page2.aspx" Text="Cross Page Postback" />

Here the form is submitted to Page2 instead to the form containing the button.

Thanks
Shanti