Different types of Applications

CLI----COMMAND LINE INTERFACE APPLICATION:
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1.By using COMMAND LINE INTERFACE we can type commands in console window and can interact with computers operating system and we can perform some specific tasks.

2.After a command is entered system merely waits for the user to conclude by pressing enter, then command line interpreter receives and executes the requested command.

3.A great advantage to a CLI is that you can always see what you did — whereas with a GUI, if you aren't paying attention when your hand slips, you may never know what happened.

4.When CLI application is intialised and processing of transactions are completed the application must be properly disconnected from the datasource and free all the resources.

5.It has no icons or pictures, and often is so simple that even a mouse will not work — it relies on the keyboard

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6. In some applications, such as MATLAB and AutoCAD, a CLI is integrated with the GUI, with the benefits of both.

7.CLIs are also popular among people with visual disability, since the commands and feedbacks can be displayed using Refreshable Braille displays.

Example: Visual studio command prompt.
Windows power shell.
Cobol




GUI---GRAPHICAL USER INTERFACE APPLICATION:
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1.A program interface that takes advantage of the computer's graphics to make the program easier to use.this can avoid the user from learning complex command languages.

2.Some of the basic components of GUI are pointer,icons.windows, menus.

3.The first graphical user interface was designed by Xerox Corporation's Palo Alto Research Center in the 1970s, but it was not until the 1980s

4.By the emergence of the Apple Macintosh graphical user interfaces became popular. One reason for their slow acceptance was the fact that they require considerable CPU power and ahigh-quality monitor, which until recently were prohibitively expensive.

5.In addition to their visual components, graphical user interfaces also make it easier to move data from one application to another.

Example: Windows7,Mac Os

THICK CLIENT AND THIN CLIENT:
THICK CLIENTS :

1.These are the networks which typically provides rich functionality independently of the central server.

2. In designing a client–server application, a decision is to be made as to which parts of the task should be executed on the client, and which on the server. This decision can crucially affect thecost of clients and servers, the robustness and security of the application as a whole, and the flexibility of the design to later modification or porting.


THIN CLIENTS:

These are designed small and bulk of data processing occurs at server side, they require constant communication with server.They provide desktop environment. Ex...schools,hospitals,airticketing,railway tickiting.

CLIENT-SERVER APPLICATIONS:
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1.It is a distributed application at which client requests for a service from service provider,server.

2.While developing this type of applications developer must consider team environmenta and long term maintainenece.

3.Sockets involve a major place in client server application.

4.In a network, the client/server model provides a convenient way to interconnect programs that are distributed efficiently across different locations.

5.This is the way to connect computers which are geographically away and we can make transactions.

**Protocols:
a)TCP/IP:
The program which uses TCP must follow these rules:

The server side would follow these steps:
Create a socket.
Listen for incoming connections from clients.
Accept the client connection.
Send and receive information.
Close the socket when finished, terminating the conversation.

In the case of the client, these steps are followed:

Create a socket.
Specify the address and service port of the server program.
Establish the connection with the server.
Send and receive information.
Close the socket when finished, terminating the conversation.

b)HTTP (HyperText transfer Protocol): used on the World Wide Web (WWW) for transfering web pages and files contained in web pages such as images.

c)FTP (File Transfer protocol): employed for transfering files from one machine to the other.

d)SMTP (Simple Mail Transport Protocol): used for email.

e)Telnet Protocol: Used to open telnet sessions.

Examples: Online banking,
Sql server management studio.

LEGACY APPLICATIONS:

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1.Legacy means outdated, legacy applications are those which are written for earlier operating system or hardware or platform but those are running in current technology.

2.We have to keep the legacy application running while converting it to newer.

3.Even after running under current technology they must be capable of running at platform they were developed for.

4.With many new tools, legacy databases can be accessed by newer programs.

5.Where it is impossible to replace legacy systems through the practice of application retirement, it is still possible to enhance them.

Examples:Windows 3.1and DOS running under windows vista
NASA (NASA's Space Shuttle program still uses a large amount of 1970s-era technology)
MAINFRAMES.

INTRANET/INTERNET:
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INTRANET:

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1.An intranet is a network that can share any part of an organization's information or network within that organization.

This is a network which is not available to outside world.

2.Refers to a network within an organization. Sometimes the term refers only to the organization's internal website, but may be a more extensive part of the organization's information technology infrastructure

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3.Intranet uses same concepts and technologies which are used for the Internet, such as client–server computing and the Internet Protocol Suite (TCP/IP).

4.As this is with in organization it can only usable by employees.

5.Benefits of intranet---Communication,cost-effective,immediate updates,cross-platform compatability,time, business operations,knowledge of your audience.

INTERNET:
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1.Internet is a global network that connects millons of computers which are geographically separated.

2.It provides online services like sharing of data

3. Internet and the Web are not same.The Internet is a global data communications system . It is a hardware and software infrastructure that provides connectivity between computers.

4. In contrast, the Web is one of the services communicated via the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks and URLs.

5.E-mail is an important communications service available on the Internet.
For both intranet and internet HTTP protocols of web which are to be followed for transfering files on www.

A browser is an HTTP client and server is an HTTPserver.

Examples:
Banking, E-commerceapplications, shopping, online ticket booking.

WEB-SERVICE Application:
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1.Web Services are a new breed of Web applications.Web applications are those which provide services by using network such as internet/intranet.

It can also be described as computer based software application that is hosted in browser control environment.

They are self-contained, self-describing, and modular applications that can be published, located, and invoked across the Web.

2. The Web Services Framework utilizes the HTTP protocol (as standard Web Application) in conjunction with XML, SOAP, WSDL and UDDI technologies.

3.Web service call composer or Web Service Tester used for testing web service apps.

4.Recent revolution in technology is service oriented approach or web service model which business over web as the e –commerce application..

Example:Online Bookstore Web Services Application, all e-commerce applications.