Web Application Development: Concepts, Design, and Security

LO1 Understand the concepts of web application development
For this various technologies are used such as Ajax, ASP.NET, CSS, CGI, Java, etc. These have risk
factors similar to desktop applications. These have a lifecycle model such as Scrum, Feature driven
development, Extreme programming and Timebox development. Testing is performed on web
applications as well. Besides it requires some additional testing also such as Accessibility, Cross-
browser, responsiveness etc.
P1.1 - Critically evaluate the functions and advantages of web applications
Functions of Web Applications: The web apps are just like any regular computer program which is
able to perform some functions with the help of web browsers. The application can be simple or
complex. In a client server type model, clients are used referring to the programs which a person is
using in order to run the application. In this type of model, more than one computer shares their
data by entering information into the database. The client application is used for entering the
information while the server application is used for storing the information. With web applications,
the developer does not need to build a client for any type of operating system. So for accessing the
application, one only needs to have a internet connection. The client runs this using a web browser,
so the application should be platform compatible. Server side scripting and client side scripting is
commonly used in web applications in order to develop them. The client side focus mainly on
information presentation and server side deals with stuffs such as information retrieving and storing.
The web applications are as old as World Wide Web. As most of the web application involves client
server model as their architecture in which the clients have to enter the information and the server
retrieves and stores them. One such example is Internet mail.
Advantages of Web Applications:
 Cost effective type development
 Ubiquitous
 Easy to customize
 Device Compatible
 Easy to install and maintain
 Adaptable
 More Security
 Flexible
 Easy to develop
 More utilization
 Easy to grow
P1.2 – Critically compare different types of server-side and client-side
scripting languages.
Client-Side: On client-side, web browser runs. JavaScript is considered as the major scripting
language at client side for web. These are interpreted with the help of the browsers. The process
involves following procedure:
1. User first requests for a web page from the server.

2. Server then finds that page and upon searching it sends it back to user.
3. Page received from server is displayed on web browser.
So we can say that it is used to make changes to the web pages upon retrieval. It is used to make
these pages more user friendly. In short it is used for interaction and appearance. It highly depends
on user's computer. Their speed will depend on user's computer.
Server Side: The server contains web pages and other data. The server sends the requested pages to
clients upon requesting. The process at server side includes:
1. User first makes a request for web page from server.
2. Then page script gets interpreted by server.
3. Then the page is sent to user.
This allows users to have their individual accounts. It provides privacy levels, personalization etc. The
two important server side scripting languages are ASP.net and PHP. This script is then interpreted by
server. The user do not sees the server side scripting because they runs on server.
P1.3 – Examine web security and make recommendations for security
improvements.
The security of web is procedure of securing data which is stored online so as to prevent any
unauthorized modification and access. For this, some stringent policy rules are needed to be
accomplished. The main aim of implementing security to web applications is:
 To identify users that can access the data
 To identify vulnerabilities
 To identify risks
 To identify critical assets
 To identify access levels
In short, the main aim of implementing web security to web applications is
1. Confidentiality: It means that sensitive information should be kept secured and should not
be exposed ay any cost.
2. Availability: It means that the web application should be available for the access of the user
upon request.
3. Non Repudiation: It means one cannot deny his presence in the whole process.
4. Integrity: It means that the data in the web applications are consistent.

LO2 Be able to design web applications
P2.1 designs a web application to meet requirements given in the case
study.
For this website, user has provided some essential requirements. These are as under:
1. The implemented website should reflect the architecture in form of 3-tiers.
2. The website should have its front and backend to be connected.
3. The home page should include the logo of the company, name of the company, a dropdown
type menu bar, the objectives and goals of the company, footer and links to navigate to
other pages.
4. Some images that can give ideas about the company.
5. There should be minimum 4 pages for user interaction.
6. The font sizes and colours should be a standard one.
7. The database should be very appropriate