Visualforce tag for Salesforce
What is the <apex:actionSupport> tag used for in Visualforce pages?
Discussion: actionSupport is a AJAX. ActionSupport : supports another component, allowing the component to be refreshed asynchronously by the server when a particular event occurs, such as a button click or mouseover. Used when we want to perform an action on a perticular even
tof any control like onchange of any text box or picklist.