ASP.NET is a web development platform, which provides a programming
model, a comprehensive software infrastructure and various services
required to build up robust web applications for PC, as well as mobile
ASP.NET works on top of the HTTP protocol, and uses the HTTP
commands and policies to set a browser-to-server bilateral
communication and cooperation.
ASP.NET is a part of Microsoft .Net platform. ASP.NET applications
are compiled codes, written using the extensible and reusable
components or objects present in .Net framework. These codes can use
the entire hierarchy of classes in .Net framework.
The ASP.NET application codes can be written in any of the
- Visual Basic.Net
ASP.NET is used to produce interactive, data-driven web
applications over the internet. It consists of a large number of
controls such as text boxes, buttons, and labels for assembling,
configuring, and manipulating code to create HTML pages.
ASP.NET Web Forms Model
ASP.NET web forms extend the event-driven model of interaction to
the web applications. The browser submits a web form to the web server
and the server returns a full markup page or HTML page in
All client side user activities are forwarded to the server for
stateful processing. The server processes the output of the client
actions and triggers the reactions.
Now, HTTP is a stateless protocol. ASP.NET framework helps in
storing the information regarding the state of the application, which
The page state is the state of the client, i.e., the content of
various input fields in the web form. The session state is the
collective information obtained from various pages the user visited
and worked with, i.e., the overall session state. To clear the
concept, let us take an example of a shopping cart.
User adds items to a shopping cart. Items are selected from a page,
say the items page, and the total collected items and price are shown
on a different page, say the cart page. Only HTTP cannot keep track of
all the information coming from various pages. ASP.NET session state
and server side infrastructure keeps track of the information
collected globally over a session.
The ASP.NET runtime carries the page state to and from the server
across page requests while generating ASP.NET runtime codes, and
incorporates the state of the server side components in hidden
This way, the server becomes aware of the overall application state
and operates in a two-tiered connected way.
The ASP.NET Component Model
The ASP.NET component model provides various building blocks of
ASP.NET pages. Basically it is an object model, which describes:
Server side counterparts of almost all HTML elements or tags,
such as <form> and <input>.
Server controls, which help in developing complex
user-interface. For example, the Calendar control or the Gridview
ASP.NET is a technology, which works on the .Net framework that
contains all web-related functionalities. The .Net framework is made
of an object-oriented hierarchy. An ASP.NET web application is made of
pages. When a user requests an ASP.NET page, the IIS delegates the
processing of the page to the ASP.NET runtime system.
The ASP.NET runtime transforms the .aspx page into an instance of a
class, which inherits from the base class page of the .Net framework.
Therefore, each ASP.NET page is an object and all its components i.e.,
the server-side controls are also objects.
Components of .Net Framework 3.5
Before going to the next session on Visual Studio.Net, let us go
through at the various components of the .Net framework 3.5. The
following table describes the components of the .Net framework 3.5 and
the job they perform:
Components and their Description
(1) Common Language Runtime or CLR
It performs memory management, exception handling, debugging,
security checking, thread execution, code execution, code safety,
verification, and compilation. The code that is directly managed by
the CLR is called the managed code. When the managed code is compiled,
the compiler converts the source code into a CPU independent
intermediate language (IL) code. A Just In Time(JIT) compiler compiles
the IL code into native code, which is CPU specific.
(2) .Net Framework Class Library
It contains a huge library of reusable types. classes, interfaces,
structures, and enumerated values, which are collectively called
(3) Common Language Specification
It contains the specifications for the .Net supported languages and
implementation of language integration.
(4) Common Type System
It provides guidelines for declaring, using, and managing types at
runtime, and cross-language communication.
(5) Metadata and Assemblies
Metadata is the binary information describing the program, which is
either stored in a portable executable file (PE) or in the memory.
Assembly is a logical unit consisting of the assembly manifest, type
metadata, IL code, and a set of resources like image files.
(6) Windows Forms
Windows Forms contain the graphical representation of any window
displayed in the application.
(7) ASP.NET and ASP.NET AJAX
ASP.NET is the web development model and AJAX is an extension of
ASP.NET for developing and implementing AJAX functionality. ASP.NET
AJAX contains the components that allow the developer to update data
on a website without a complete reload of the page.
It is the technology used for working with data and databases. It
provides access to data sources like SQL server, OLE DB, XML etc. The
ADO.NET allows connection to data sources for retrieving,
manipulating, and updating data.
(9) Windows Workflow Foundation (WF)
It helps in building workflow-based applications in Windows. It
contains activities, workflow runtime, workflow designer, and a rules
(10) Windows Presentation Foundation
It provides a separation between the user interface and the
business logic. It helps in developing visually stunning interfaces
using documents, media, two and three dimensional graphics,
animations, and more.
(11) Windows Communication Foundation (WCF)
It is the technology used for building and executing connected
(12) Windows CardSpace
It provides safety for accessing resources and sharing personal
information on the internet.
It imparts data querying capabilities to .Net languages using a
syntax which is similar to the tradition query language SQL.