The output below is the return value of a php script which takes four seconds to reply to each AJAX request. It is called again after a one second interval, only when a response has been received. A new number should appear here no faster than once every five seconds.
The output below is the return value of a php script which replies immediately to each AJAX request. It is called again on a one second interval, regardless of whether or not a response has been received. A new number should appear here at the most once every second.
Both of these repeating AJAX requests begin on pageload.