Active Server Pages and Active Client Pages - AJAX
If a user were using a slow Internet connection, he would have found that it takes time for him to have his web page displayed (downloaded) at his client computer. Nowadays, only the first page of his web site will take a long time to be downloaded; the rest of the pages will come very fast. Keep reading to learn how we can accomplish this trick. It's all thanks to Active Client Pages and the magic of AJAX.
Many professional web sites use server-side applications like PHP, ASP, JSP etc. to generate their pages. All of these systems produce HTML pages at the server, based on data (or some non-standard information) at the server. Active Client Pages, on the other hand, produce HTML pages in the browser at the client, but still use data or information stored at the server. Well, with Active Client Pages, the very first page may be produced at the server. In practice, the rest of the pages, which are produced at the client, are actually downloaded from the server in advance as texts (strings with escaped entities).
Definition of Active Client Pages
We've read enough of a preamble to understand the definition of Active Client Pages. The definition I am giving you here is my definition. It is not what Vlad or Chuck has given. Active Client Pages are defined as the production of HTML pages at the client computer by the browser using web technology.
The data or information for the HTML pages reside at the server. You need a client script language, such as JavaScript, to produce the HTML pages at the client. I use JavaScript in my articles. I will write many articles using ACP. Let me now welcome you to the exciting world of Active Client Pages.
AJAX & Prototype 
