ASP Basics

What is ASP?

• ASP stands for Active Server Pages
• ASP is a program that runs inside IIS
• IIS stands for Internet Information Services
• IIS comes as a free component with Windows 2000
• IIS is also a part of the Windows NT 4.0 Option Pack
• The Option Pack can be downloaded from Microsoft
• PWS is a smaller - but fully functional - version of IIS
• PWS can be found on your Windows 95/98 CD

Advantages Using ASP.NET

• ASP.NET drastically reduces the amount of code required to build large applications
• ASP.NET makes development simpler and easier to maintain with an event-driven, server-side programming model
• ASP.NET pages are easy to write and maintain because the source code and HTML are together
• The source code is executed on the server. The pages have lots of power and flexibility by this approach
• The source code is compiled the first time the page is requested. Execution is fast as the Web Server compiles the page the first time it is requested. The server saves the compiled version of the page for use next time the page is requested
• The HTML produced by the ASP.NET page is sent back to the browser. The application source code you write is not sent and is not easily stolen
• ASP.NET makes for easy deployment. There is no need to register components because the configuration information is built-in
• The Web server continuously monitors the pages, components and applications running on it. If it noticies memory leaks, infinite loops, other illegal software or activities, it seamlessly kills those activities and restarts itself
• ASP.NET validates information (validation controls) entered by the user without writing a single line of code
• ASP.NET easily works with ADO .NET using data-binding and page formatting features
• ASP.NET applications run fater and counters large volumes of users without performance problems

Differences between ASP.NET and Client-Side Technologies

Client-side refers to the browser and the machine running the browser. Server-side on the other hand refers to a Web server.

Client-Side Scripting

Javascript and VBScript and generally used for Client-side scripting. Client-side scripting executes in the browser after the page is loaded. Using client-side scripting you can add some cool features to your page. Both, HTML and the script are together in the same file and the script is download as part of the page which anyone can view. A client-side script runs only on a browser that supports scripting and specifically the scripting language that is used. Since the script is in the same file as the HTML and as it executes on the machine you use, the page may take longer time to download.

Server-Side Scripting

ASP.NET is purely server-side technology. ASP.NET code executes on the server before it is sent to the browser. The code that is sent back to the browser is pure HTML and not ASP.NET code. Like client-side scripting, ASP.NET code is similar in a way that it allows you to write your code alongside HTML. Unlike client-side scripting, ASP.NET code is executed on the server and not in the browser. The script that you write alongside your HTML is not sent back to the browser and that prevents others from stealing the code you developed

Features

• Improve the reliability and usability of Web applications
• Reduce the number of lines of code you have to write in common scenarios
• Offer user features to personalize Web applications
• Provide enhanced design features to generate consistent layouts and design

ASP.NET architecture

As the illustration shows, all Web clients communicate with ASP.NET applications through Microsoft Internet Information Services (IIS). IIS deciphers and optionally authenticates the request. If Allow Anonymous is set to true, no authentication occurs. IIS also finds the requested resource (such as an ASP.NET application), and, if the client is authorized, returns the appropriate resource.

In addition to the built-in ASP.NET security features, an ASP.NET application can use the low-level security features of the .NET Framework.