Study Style

These are components that allow web developers to create server-side scripted templates that generate dynamic, interactive web server applications. By embedding special programmatic codes in standard HTML pages, a user can access data in a database, interact with page objects such as Active-X or Java components, or create other types of dynamic output. The HTML output by an Active Server Page is totally browser independent, which means that it can be read equally well by Microsoft Explorer, Netscape Navigator, or most other browsers. The code for this scripting can be written in any of several languages, and is embedded in special tags inside the otherwise normal HTML code making up a page of content.

The Static Internet

The web server did not dynamically generate any part of the sites contents but simply served requests for static HTML pages loaded from the web server's file system and sent to the requesting client.

The Dynamic Internet

. CGI Applications (Common Gateway Interfaces)
It provides a mechanism by which a web browser can communicate a request for the execution of an application on the web server. The result of this application is converted/formatted into a browser readable (HTML) form and sent to the requesting browser.

. ISAPI Applications (Internet Server Application Programming Interface)
In CGI applications the web server has to instantiate a new application every time a request in made. In ISAPI, to relay this problem having the DLL (Dynamic Link Libraries). Once the ISAPI application DLL is loaded into memory, it stays in memory. The web server does not need to load it again.

In addition to ISAPI applications, ISAPI allows for the development of ISAPI filters. An ISAPI filter is a custom DLL that is in the same memory space as the web server and is called by the web server in response to every HTTP request, and it instructs the web server how to handle the request. A security layer between the client and the web server it provides page-level security.

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