It is a real time communicating with server. there are two different way for doing this things. One is Jquery method and another is XMLHttpRequest object method.
Example: Google auto suggetion method is actually ajax call
$.ajax({ type: "POST", url: url, data: data, success: success, dataType: dataType });
Url: which file will pare the sending data.
type: POST, GET Or REQUEST
data : javascript variable data
success: on data successfully goes to the server .
it is a call back function.
that will come from server after data processing in server.
dataType :which type data you want to receive from server.there are several
type data.
Like -xml, json, script, text, html
