We provide web development Internet has transformed the business
around the world into one global market enabling us with the access to instant
business information at the click of a mouse.
Web based applications are becoming the key
part of business strategies across the world. They have opened the whole world
of Internet, Intranet, and Extranet based web applications.
Web applications are popular due to the compatibility of
web browsers, and the convenience of using a web browser as a client,
sometimes called a thin client. The ability to update and maintain web
applications without distributing and installing software on potentially
thousands of client computers is a key reason for their popularity, as is the
inherent support for cross-platform compatibility. Common web applications
include webmail, online retail sales, online auctions, E
Shopping and many other functions.
Applications are usually broken into logical
chunks called "tiers", where every tier is assigned a role. Traditional
applications consist only of 1 tier, which resides on the client machine, but
web applications lend themselves to a n-tiered approach by nature. Though
many variations are possible, the most common structure is
the three-tiered application. In its most common form, the three
tiers are called presentation, application and storage,
in this order. A web browser is the first tier (presentation), an engine using
some dynamic Web content technology (such
as ASP, ASP.NET, CGI, ColdFusion, JSP/Java, PHP, Perl, Python, Ruby
on Rails or Struts2) is the middle tier (application logic), and a
database is the third tier (storage). The web browser sends requests to
the middle tier, which services them by making queries and updates against the
database and generates a user interface.
For more complex applications, a 3-tier
solution may fall short, and it may be beneficial to use an n-tiered approach,
where the greatest benefit is breaking the business logic, which resides on the
application tier, into a more fine-grained model. Another benefit may be
adding an integration tier that separates the data tier from the rest of tiers
by providing an easy-to-use interface to access the data. For example, the
client data would be accessed by calling a "list clients ()" function
instead of making an SQL query directly against the client table on the
database. This allows the underlying database to be replaced without making any
change to the other tiers.