we can find the ID property in every control. The IDE sets this property and we need it to refer to the control from elsewhere on the page.
AJAX is a technique that is used for shifting much of the processing off the server and to the user's browser, which dramatically increases the performance, both actual and perceived.
To use ajax controls, we need to add a ScriptManager control to the page.
The EnablePartialRendering property is the critical property of the ScriptManagercontrol, which is why it is set to True by default.
We can use The UpdatePanel control to enables asynchronous updates.