Difference between AutoPostBack=True and AutoPostBack=False?

Taken from http://www.dotnetspider.com/resources/189-AutoPostBack-What-How-works.aspx:

Autopostback is the mechanism by which the page will be posted back to the server automatically based on some events in the web controls. In some of the web controls, the property called auto post back, if set to true, will send the request to the server when an event happens in the control.

Whenever we set the autopostback attribute to true on any of the controls, the .NET framework will automatically insert a few lines of code into the HTML generated to implement this functionality.

1. A JavaScript method with name __doPostBack (eventtarget, eventargument)
2. Two hidden variables with name __EVENTTARGET and __EVENTARGUMENT
3. OnChange JavaScript event to the control

AutoPostBack = true permits control to post back to the server. It is associated with an Event.

Example:

<asp:DropDownList id="id" runat="server" AutoPostBack="true" OnSelectIndexChanged="..."/>

The aspx page with the above drop down list does not need an asp:button to do the post back. When you change an option in the drop down list, the page gets posted back to the server.

Default value of AutoPostBack on control is false.

AutopostBack is a property which you assign to web controls if you want to post back the page when any event occurs at them.

You may see this article: What is AutoPostBack?

Autopostback is the mechanism, by which the page will be posted back to the server automatically based on some events in the web controls. In some of the web controls, the property called auto post back, which if set to true, will send the request to the server when an event happens in the control

For example, TextBox has AutoPostBack property

Use the AutoPostBack property to specify whether an automatic postback to the server will occur when the TextBox control loses focus. Pressing the ENTER or the TAB key while in the TextBox control is the most common way to change focus.