EDI was developed to solve the problems inherent in paper-based transaction processing and in other forms ofelectronic communication. Implementing EDI system offers a company greater control over its supply chain and allow it to trade more effectively. It also increases productivity and promotes operational efficiency.
The following are the other advantages of EDI.
(i) Improving service to end-users
(ii) Increasing productivity
(iii) Minimizing errors
(iv) Slashing response times
(v) Automation of operations
(vi) Cutting costs
(vii) Integrating all business and trading partners.
(viii) Providing information on process status
(ix) Optimizing financial ratios.

Encryption technology is an effective information security protection. It is defined as converting a plaintext into meaningless ciphertext using encryption algorithm thus ensuring the confidentiality of the data. The encryption or decryption process use a key to encrypt or decrypt the data. At present two encryption technologies are widely used. They are symmetric key encryption system and an asymmetric key encryption system. Thre figure below shows the Data Encryption and Decryption process:

Apart from card based payment systems there are many alternative electronic payment systems. With the advent of computers, network technologies and electronic communications a large number of alternative electronic payment systems have emerged. These include ECS (Electronic Clearing Services), EFT (Electronic funds transfers), Real Time Gross Settlement system (RTGS) etc. These Electronic Payment systems are used in tendering cash in domestic and international transactions.
Electronic Clearing Services (ECS):
Electronic Clearing Service can be defined as repeated transfer of funds from one bank account to multiple bank accounts or vice versa using computer and Internet technology. The payer instructs the bank to debit from his bank account and credit it to one or more payee bank account provided amounts and dates of the payments earlier. This system provides the convenience of paperless payments. ECS can be used for both credit and debit purposes i.e. for making bulk payments or bulk collection of amounts.
Electronic Funds Transfer:
Electronic Funds Transfer (EFT) is the "electronic transfer" of money over an online network. The amount sent from the sender's bank branch is credited to the receiver's bank branch on the same day in batches. Unlike traditional processes, EFT saves the effort of sending a demand draft through post and the inherent delay in reaching the money to the receiver. Banks may charge commission for using this service. EFT is a widely used method for moving funds from one account to another in B2B business models.
Real Time Gross Settlement:
Real Time Gross Settlement System (RTGS) is a payment system particularly used for the settlement of transactions between financial institutions, especially banks. As name indicates, RTGS transactions are processed at the realtime. RTGS payments are also called as push payments that are initiated ("triggered") by the payer. RTGS payments are generally large-value payments, i.e. high-volume transactions.
Real-time gross settlement transactions are:
Unconditional: the beneficiary will receive funds regardless of whether he fulfills his obligations to the buyer or whether he would deliver the goods or perform a service of a quality consistent with the order.
Irrevocable: a correctly processed transaction cannot be reversed and its money cannot get refunded (the so-called settlement finality).

(i) Business to Business (B2B);
(ii) Business to Consumer (B2C);
(iii) Business to Government (B2G);
(iv) Consumer to Business (C2B);
(v) Consumer to Consumer (C2C);
(vi) Consumer to Government (C2G);
(vii) Government to Business (G2B);
(viii) Government to Consumer (G2C);
(ixg) Government to Government (G2G)
Business to Consumer (B2C):
(i) In B2C E-Commerce, commercial transactions take place between business firms and their consumers.
(ii) It is the direct trade between companies and end-consumers via the Internet.
(iii) B2C companies sell goods, information or services to customers through online in a more personalized dynamic environment and is considered as real competitor for a traditional storekeeper.
(iv) An example of B2C transaction is a book company selling books to customers.
Business to Government (B2G):
(i) B2G is a business model that refers to business organizations sells products, services or information to Governments or to its administrations.
(ii) In other words, when a company get paid for its goods, services by the Government through Internet it is called as B2G model.
(iii) e.g. The Government or its administration buys laptops for students.
Consumer to Business (C2B):
(i) C2B can be described as a form of E-Commerce where, the transaction is originated by the consumers.
(ii) The consumers will fix a requirement or specific price for a service or a commodity. C2B model, is also called as reverse auction model.
(iii) Here, customer bid his price for a service or a product. Then E-Commerce business entity will match the requirement of the consumer to the best possible extent.
(iv) These websites generate revenue through affiliate links, sponsored advertisement or even a small commission in every booking. c.g. Name-your-price websites.
Consumer to Consumer (C2C):
(i) C2C in E-Commerce provides opportunity for trading of products or services among consumers who are connected through the Internet.
(ii) Here the websites act as a platform to facilitate the transaction. The electronic tools and Internet infrastructure are employed to support transactions between individuals.
(iii) It means that a consumer would contact a business in search of a suitable customer. Most of the auction websites and matrimonial websites are working on this methodology.
(iv) For example, a consumer who wants to sell his property can post an advertisement on the website (eg:timesclassifieds.com).
 

OSS projects are collaboration opportunities that improve skills and build connections in the field.
Domains that developers can contribute to the open source community include:
1. Communication tools.
2. Distributed revision control systems.
3. Bug trackers and task lists.
4. Testing and debugging tools.
(i) There are many open source softwares. So, we can select and use any software that suits our needs.
(ii) The complete options of the software can be used without any cost and restrictions.
(iii) We can share our ideas with the team. write the required code and share it with many.
(iv) As we can identify the programming techniques of group members, we can learn many ideas and make our program writing skills more efficient.
(v) The coding in open source software are being groomed by many enthusiastical members of the groups. So, if we report problems that we have in the program they are quickly mended by the group's effort.
(vi) As we can make changes to the open source software, we can add the most required features in the software.
(vii) Many open source software are very user friendly.
 

There are many types of cables available in the networking
(i) Coaxial-cables:
(i) Coaxial cable is used to connect the television sets to home antennas.
(ii) It has a copper wire inside and insulation is covered on the top of the copper wire to provide protection to the cable.
(iii) It is very difficult to install and maintain, because they are too big to carry and replace.
(iv) This cable is used to transfer the information at 10 mbps speed. The cable is classified into thinnet and thicknet cables.
(ii) Twisted-Pair Cables:
(i) It is a type of cable with two or more insulated wires twisted together.
(ii) This twisted cable has 8 wires which are twisted to ignore electromagnetic interference.
(iii) There are two types of twisted pair cables, Unshielded Twisted Pair (UTP) and Shielded Twisted pair (STP).
(iii) Fiber Optics:
(i) This cable is made by using strands of glass. It uses pulses of light to send the information.
(ii) They are mainly used in Wide Area Network (WAN). These cables are placed in deep underground to avoid any damage to the cables.
(iii) There are two types of fiber optic cables available, One is single-mode another one is Multimode..
(iv) USB Cables:
(i) The Universal Serial Bus are used to connect keyboard, mouse and other peripheral devices.
(ii) Micro USB is a miniaturized version of the USB used for connecting mobile devices such as smart phones, GPS devices and digital camers.
(v) Serial and parallel cables:
(i) Before Ethernet cable was invented, the Serial and Parallel interface cables were used to connect the system to-the Internet.
(ii) They were sometime used for PC to PC networking.
(iii) E.g. RS232 cable. The serial cable send I bit at time whereas the parallel port send 8 bit at a time.
(vi) Ethernet Cables:
(i) This is a type of twisted pair cable. It is the most common type of network cable mainly used for connecting the computers or devices at home or office.
(ii) This cable connects wired devices within the local area network (LAN) for sharing the resources and accessing Internet

DNS Works:
(i) When the user enters the URL in the browser, the system first checks it DNS cache for the corresponding IP address.
(ii) If the IP address is found in the cache, then the information is retrieved from cache.
(iii) If not, the system needs to query the resolver about the IP address from Internet Service Provider (ISP).
(iv) Each resolver has its own cache and if it is found in that then that information is retrieved.
(v) If not, then the query is passed to next domain server i.e., TLD (Top Level Domain) which reviews the request and direct the query to name servers associated with that specific domain.
(vi) Unitil the query is solved it is passed to next level domians. finally, the IP address is detected and the corresponding record is sent to the resolver.
(vii) Then the resolver returns the record back to the computer browser. Now the user can view the webpages for the detected IP address.

Development of Mobile Networks :
The generations of mobile networks are as follows.
(i) First Generation(1G) 1981- NMT launch
(ii) Second Generation(2G) 1991-GSM Launch
(iii) Second to Third Generation Bridge (2.5)2000 — GPRS launch
(iv) Third Generation( 3G) 2003- UK 3G launch
(v) Fourth Generation (4 G) 2007
(vi) Fifth Generation (5G) 2019+
Merits of Mobile Networks :
(i) It provides both voice/data services.
(ii) It connects both fixed and wireless telephone users.
(iii) It is used in areas where cables cannot be laid out due to its wireless nature.
(iv) It is easy to maintain.
(v) It is easy to upgrade the equipments.
(vi) The ‘mobile and fixed subscribers are connected immediately with cellular network as soon as mobile phones are switched on.
(vii) All the handshake signals between mobile and base station are automatically exchanged.
Demerits of Mobile Networks :
(i) Cost
(ii) Vulnerable to Security risks
(iii) Additional training is needed to use new technology.
(iv) Cyber Crime.

1. The uses of the computer networking are:
2. It is used in business and home
3. Growth on popularity of cloud storage and cloud computing.
4. On behalf of buying physical copies of games music and movies, increasingly downloading and buy digital license their need via internet.
5. Developments on mobile networking infrastructure both deployments of 4G and 3G networks that will allow the people in their developed areas.
6. Allows it to their smart mobile phones as video broadcasting system and as mobile television.
7. Some of the people underlying and staying connected all the times, whenever they are at the workplace, via a home network, via publish WiFi hotspots or smart phone.
8. 4G LTE mobile network was not reached by many parts of world, of the industry of telecommunication has been hard working on the development of their next generation :"5G" cellular communication technology. This 5G intense to boost up the speed the mobile connections dramatically.
9. Artificial intelligence will help to maintain, manage, and protect it.
10. This Artificial network powering algorithms with become most intelligent:
11. It might find faster and reliable methods of anticipating threats and cleaning networks.
12. Artificial intelligence able to be a better predict traffic as it collects and analyses data in real time, some of network managers were better prepared for big event such as the world cup, Olympics, Valentines day which often put on the Internet under pressure.

MySQL function in PHP:
In PHP Scripting language many functions are available for MySQL Database connectivity and executing SQL queries.
MySQLi is extension in PHP scripting language which gives access to the MYSQL database. MySQLi extension was introduced version 5.0.0,
The MySQLi extension contains the following important functions which are related to MySQL database connectivity and management.
i) Mysqli_connect() Function
ii) Mysqli_close() Function
iii) Mysqli_query() Function
(i) Database Connections:
Before accessing MySQL Database, connect to Database Server machine via PHP scripting language using Mysqli_connect() Function.
Syntax :
mysqli_connect("Server Name "User Name","Password"DB Name");
This function requires four parameters to connect to database server. Database Server name, Database username, password anda Database Name.
(ii) Managing Database Connections :
The below code describes managing database connection methods and features.

The mysqli_connect function uses these variables to connect Database server to PHP. If connection gets fail, output will be printed with MySQL error code. Otherwise connection is success.
(iii) Performing Queries :
The main goal of MySQL and PHP connectivity is to retrieve and manipulate the data from MYSQL database server. The SQL query statements help in PHP MySQL extension to achieve the objective of MYSQL and PHP connection. "mysqli_query" is a function, that helps to execute the SQL query statements in PHP scripting language.
Syntax:
mysqli_query("Connection Object","SQL Query")
Example:

Closing Connection :
mysqli_close() Function is used to close an existing opened database connection between PHP scripting and MySQL Database Server.

PHP Basic Form Handling:
(i) When the user keys in the input data in HTML controls and clicks the submit button the request will be generated and reaches a PHP file which is mentioned in the FORM tag under the Action attribute.
(ii) All the input values are synchronized and sent to the server via POST method or GET method. Method is an attribute of form tag in HTML.
(iii) Once the data reaches the server,two PHP variables such as \($\)_POST and \($\)_GET collects the data and prepares the response accordingly.
Post Method: The input data sent to the server with POST method is stored in the request body of the client's HTTP request.
Get Method: The input data sent to the server with POST method via URL address is known as query string. All input data are visible by user after they clicks the submit button.
Example:
Test.html:
< html >
< body >
<form action="'welcome.php" method=''post" >
Name: < input type="text" name="name'' > < br >
E-mail: < input type="text" name="email" > < br >
< input type=''submit" >
< /form >
< /body >
< /html >
Welcome.php:
< html >
< body >
Welcome < ?php echo  \($\)_POST["name"]; ? > < br >
Your email address is: < ?php echo  \($\)_POST["email"]; ? >
< /body >
< /html >
Output

(i) HTML File contains two Text Box (Name and Email), One Button and one form tag. The remote server PHP file (welcome.php) is mentioned in form tag under the Action Attribute.
(ii) In "Welcome.Php" file, PHP variables such as \($\)_POST and \($\)_GET collects the data and prepares the response accordingly.
(iii) Eventually the user will receive the output response in the client machine's browser screen.

Looping structure are useful for writing iteration logics. It is the most important feature of many programming languages including PHP.
Looping categories are
(i) for loop
(ii) for each loop
(iii) while loop
(iv) Do while loop
(i) for loop:
It is used for iteration logics when the programmer know in advance how many times the loop should run.
Syntax:
for (init counter; test counter; increment counter)
{
code to be executed;
}
Parameters:
init counter: To initialize the loop initial counter value
test counter : Evaluated for every iteration, of the loop.
If it evaluates to TRUE, the loop continues.
If it evaluates to FALSE, the loops ends.
Increment counter:Increases the loop counter value.

(ii) for each loop:
It works only with arrays.
Loop iteration depends on each KEY value pair in the Array.
In loop iteration, value of the current array element is assigned to $value variable and the array
pointer is shifted by one until it reaches the end of the array element.
Syntax:
for each ($array as $value)
{
code to be executed;
}
(iii) While loop:
It is used for simple iteration logics.
It checks the condition, if the condition is true, and it executes the loop.
Syntax:
while (condition is true)
code to be executed;
}
(iv) Do while loop:
Do while loop always run the statement inside the loop block at the first time of execution. It then checks the condition. If the specified condition is true, it executes the loop.
Syntax:
do
{
code to be executed;
}while (condition is true);
}

Conditional statements in PHP are implemented by the following types:
(i) if Statement
(ii) if... else Statement
(iii) if... elseif... else Statement
(iv) switch Statement
(i) If statement in PHP:
If statement executes a statement or a group of statements if a specific condition is satisfied as per the
user expectation.
Syntax:
if (condition)
{
Execute statement(s) if condition is true;
}
(ii) If else statement in PHP:
If statement executes a statement or a group of statements, if a specific condition is satisfied by the user
expectation. When the condition gets false (fail) the else block is executed.
Syntax:
if (condition)
{
Execute statement(s) if condition is true;
}
else
{
Execute statement(s) if condition is false;
(iii) If elseif else statement
It is a combination of if-else statement. More than one statement can execute the condition based on user needs.
Syntax:
if (1st condition)
{
Execute statement(s) if condition is true;
}
elseif (2nd condition)
{
Execute statement(s) if 2nd condition is true;
}
else
{
Execute statement(s) if both conditions are false;
}
(iv) Switch Statement
It is used to perform different actions based on different conditions.
Syntax:
switch (n) {
case label 1:
code to be executed if n-label1;
break;
case label2:
code to be executed if n=label2;
break;
***
default:
code to be executed if n is different from all labels;
}

Multidimensional Arrays:
Array containing one or more arrays is called multidimensional array. PHP accepts array with two, three four or more levels.
Example:
// A two-dimensional array
$student=array
(
array("Iniyan", 100, 96),
array("Kavin", 60, 59),
array("Nilani", 1313, 139)
);
echo ＄＄student [0][0].": Tamil Mark: ".＄student [0][1].". English mark: ".＄student [0] [2]."< br >";
echo ＄＄student [1][0].": Tamil Mark: ".＄student [1][1].". English mark: ".＄student [1] [2]."< br >";
echo ＄＄student [2}[0].": Tamil Mark:".＄student [2][1].".English mark: ".＄student [2] [2]."< br >
? >

The following are the steps to install and configure Apache Httpd webserver and PHP module in windows server machine.
Step 1:
Go to Apache foundation website and download the Httpd webserver software.
https://httpd.apache.org/download.cgi.
Step 2:
After downloading MSI file from Apache foundation website, user launches the MSI file and clicks next.
Click on next and next button finish the installation on server machine.
Software takes default port number 130 or 130130.
Once the user finished, webserver software is installed and configured on server hardware machine as a service.
Step 3:
To test the installation of Apache Httpd webserver, enter the following URL. from your web browser which is installed in your client machine.
https://localhost:130/ (or) https://localhost:130130
The output page that says "Its works"
Step 4:
Administrator user can start, stop and restart the webserver service at any time via windows control panel.
Once the services stops, the client machine will not receive the response message from server machine.
Step 5.
Webserver's configuration setting file "httpd.conf" is located in the conf directory under the apache installation directory.
Edit this file and enable the PHP module to run PHP scripting language.

An attribute is the information about entity and it will describe, qualify, quantify, classify, and specify an entity.
An attribute will always have a single value, that value can be a number (or) character (or) string.
Types of Attributes: 
(1) Key Attribute
(2) Simple Attributes
(3) Composite Attributes
(4) Single Valued Attribute
(5) Multi Valued Attribute.
1 Key Attribute:- Generally a key attribute describes a unique characteristic of an entity.
2. Simple Attributes:- The Simple Attributes cannot be separated it will be having a single value for their entity.
For Example: Let us consider the name as the attribute for the entity employee and here the value for that attribute is a single value.

3. Composite Attributes:- The composite attributes can be subdivided into simple attributes without change in the meaning of that attribute.
For Example: In the above diagram the employee is the entity with the composite attribute Name
which are sub-divided into two simple attributes first and last name.
4. Single Valued Attributes:- A single valued attribute contains only one value for the attribute and they don't have multiple numbers of values.
For Example: Age- It is a single value for a person as we cannot give n number of ages for a single

5. A Multi Valued Attributes:- A multi valued attribute has more than one-value for that particular attribute.
For Example: Degree A person can hold n number of degrees so it is a multi-valued attribute.

To place text in a Frame
(i) Click on any one Frame tool from the Toolbox.
(ii) Draw a frame with one of PageMaker's Frame tools (Rectangle frame tool (or) Ellipse Frame Tool (or) Polygon frame Tool). Make sure the objects remains selected.
(iii) Click on File > Place. The Place dialog box will appears.
(iv) Locate the document that contains the text you want to place, select it.
(v) Click on Open.
(vi) Click in a frame to place the text in it.The text will be placed in the frame.

1. Animation is the process of displaying images with continuous movement.
2. In animation, the screen object is a vector image in animation.
3. Using numerical transformations the movement of that image along its path is calculated for their defining coordinates.
4. The least frame rate of atleast 16 frame/sec gives the impression of smoothness and for natural looking it should be atleast 25 frame/sec.
5.  Animations may be in two or three dimensional.
6. The two dimensional animation, bring an image alive, that occur on the flat X and Y axis of the screen, while in three dimensional animation it occurs along the three axis X, Y and Z.
7. The two basic types of animations are (1) Path animation and (2) Frame animation.
(1) Path Animation
It involves moving an object on a screen that has a constant background.
E.g. A cartoon character may move across the screen regardless of any change in the background or the character.
(2) Frame Animation
In frame animations, multiple objects are allowed to travel simultaneously and the background also changes.