Hyper Text Markup Language

What is
Hyper Text Markup Language

HTML stands for Hyper Text Markup Language. It is a formatting language used to develop web pages. Hypertext means that HTML makes certain words in the document as links to other parts of the same document or other document. When the user clicks on a link, the browser starts displaying the document attached to the link.

HTML is not a programming language. It is used to define text, graphics, audio and video in web pages. It uses tags or markups to specify how the concept of web pages will be displayed. HTML code can be written in any text editor like notepad.

HTML was developed a few years ago as a subset of SGML. SGML stands for Structured Generalized Mark-up Language. It also describes formatting and hypertext links and different component of a document. It is basically an application oriented document format. SGMl is not ideal for transmission across the Internet to different type of computers and browser applications.

HTML is simpler then SGML. It was designed for the use over the Internet in the form of Web pages. HTML is more suited for this purpose. It is used to design and create pages for different types of users of the Web.

Benefits and Limitation of HTML

Benefits of HTML

Why we use HTML ? Ofcorse there are some benefits of it. These are some of its benefits.

Simplicity

HTML is simple but powerful language. Any person can use HTML to create his own Web pages with just a little effort.

Platform Independent

HTML is platform independent. It works on any platform. HTML documents created for one type of system can be used on other systems as well.

Easy Navigation

HTML web pages are linked together using hyperlinks. It provides easy navigation between different documents.

Attractive and Easier to Read

HTML allows the use of graphics and animation. It delivers richer content and arrange the content creatively.

Limitations of HTML

As there are two sides of a coin, as there are some limitations of HTML. These are some of its limitations.

No Programming Capabilities

HTML provides no programming capabilities. It only provides formatted text, pictures and sounds etc.

Static

HTML can only be used to create static web pages.

Structure of HTML document

Structure of HTML document

The basic structure of HTML document is like that :

< HTML>
< HEAD>
....Your Text.... }------> Heading Section
< /HEAD >

< BODY>
....Your Text....}--------> Actual Text
< /BODY >
< /HTML >

In every HTML document, and tags indicate the begining and end of the document respectively. These tags inform the browser that the document is an HTML file. All other HTML tags must be written within these tags. The v document can be divided into two sections:

1-Header Section
2-Body Section

Header Section

and tags identify the heading or title of document. The text between these tags appears as title in the browser's window. Its length should not be more than 60 characters.

Body Section

The body of an HTML document contains the text that is displayed on a web page. The body section is enclosed within and tags. It gives a description of the document layout and structure.

DATABASE

What is DATABASE ?

Database is an organized collection of related data that is stored in an efficient and compact manner. The word organization means that data is stored in such a way that the user can use this data easily. The word related means that a database is normally created to store the data about a particular topic. The word efficient means that the user can search the required data quickly. The word compact means that the stored data occupies as little space as possible in computer.

Some examples of database are :

Phone Directory

It is a simple example of a database. A phone directory stores the phone numbers of different persons. Any phone number from the phone directory can be searched easily because all phone numbers are stored in an organized way.

Library

A library contains thousands of books. A database system can be used to store the records of books. The database can be used to search the required books easily.

Accounts

A database is used to control the accounts system of an organization. The accounts database keeps the record of all financial transactions of the organization.

College Record

A college has many students in different classes. A database is used to store the records of the students, fee transactions, examination information and attendance of the students.
These are few simple examples of database. The list is almost endless.

Database Management System

Database Management System

A database management system (DBMS) is a collection of computer programs that are used to create, maintain and access database in a convenient and efficient manner.

Characteristics

The most important characteristics of database management system are :

1-Efficiency
2-Compactness

Efficiency

A database management system stores, retrieves and manipulates data in a database with efficiency. It takes far less time to manipulate data as compared to file system. It uses the processing power of the computer to increase its efficiency.

Compactness

Compactness refers to the way of storing data in a database. A database management system stores data in less space than file system. The storage capacity of the computer is used properly.

Services of Internet

Services of Internet

Internet has provided easy way to share information and data but there are so many services which is available on the Internet. Following are some important services of the Internet.

Advertisement

Internet is used for the advertisement of different products. Manufacturers provide information about their products. In this way, they give more exposure to their products.

Online Shopping

Now it is possible for a user to buy a product using Internet. there are many online shopping store where we can see products and their prices. We can simply order these products using a credit card.

Flight Information

Airlines provide the schedule of flights on their websites. We can easily get latest information on flights arrivals and departures.

Television Station

Almost all T.V channels have their website which is used to provide information about the programs, the latest news and special events. Some televisions show their events live on their website.

Encyclopedia Publisher

Online encyclopedias are available. You can find detailed information on any topic in the world. Wikipedia is an example of it.

Search Engines

search engine is a website that provides you the facility to find the required websites on a particular topic. You can find thousands of websites about any topic. The famous search engines are Google, AltaVista, Yahoo and Lycos etc.

Medical

Many websites in the world provide detailed information on diseases. You can also consult a panel of on-line Doctors to get the advise about any medical problem.

History of Internet

History of Internet

The work on Internet was started in 1960's during the cold war of Russia and America. A network of 4 computers was developed at start.

ARPANET

During the cold war, Russia launched Sputnik satellite and America developed a network. Its name was ARPANET. It was developed for Advance Research Project Agency (ARPA).

Protocol

Protocol is a collection of rules. In 1970's NCP (Network Control Protocol) was developed. It was the first standard protocol for data transfer.

DARPA

It stands for Defense Advanced Research Projects Agency. It was a new name of ARPA . Now 37 computers were connected together. It started work to share data not only to a single network but also among other different networks. Stanford Research Institute took part in this research.

TCP/IP

A team of Stanford Research Institute developed a protocol called TCP/IP . It stands for Transmission Control Protocol/Internet Protocol. It was designed to share data among different networks.

BITNET AND CSNET

BITNET stands for Because It's Time Network and Csnet stands for Computer Science Network. These were established for non-military persons. These networks were used for academic and research purpose. In these networks, IBM computers and university computers were connected together.

World Wide Network

Soon the idea of Internet same out. Different universities and Research institutes started work on a global network. In 1986, NSFNet was developed. It connected academic researches of different countries.

Internet

Internet is now the largest network in the world. millions of computers are connected together through different medium. People can share information and data. Any computer with a modem and telephone line can become part of the Internet

Food Preservation - Principle 4

Reduction in Physical Defects { Principle 4 }

Food is also spoiled by physical defects during handling and processing. These physical defects should be reduced to avoid food spoilage, as is is told in principle 4 of food preservation. Surface drying and crystallization are the most common physical defects. These must be controlled.

Surface Drying

The drying out observed on the surface of certain foods during frozen storage is an important physical defect that can be controlled by proper packaging and maintenance of a steady storage temperature. If more humidity is maintained in storage , then surface drying can be minimized. The use of ultra violate lamp in storage is also helpful.

Crystallization

Another common physical defect involves crystallization (formation of small pieces) of sugar form syrups and other sugar based products. Such defective products develop a bad taste. This can be prevented by using a mixture of of two or more sugars instead of single sugar. A solution having 60% sucrose( a sugar) will develop crystals. whereas a solution containing 75% total sugars made up of careful blend of sucrose(a sugar), glucose(a sugar) and fructose (a sugar) will show no visible signs of crystals.

Food Preservation - Principle 3

Control of Pest Activities {Principle 3 }

Principle 3 of food preservation tells that food can be saved from spoilage damage caused by pest (these are also insects but they compete with Human for food). Insects, rodents and birds have attained pest status in most countries. These cause heavy damage to food stuff. these are a constant threat to man's survival. These must be controlled to avoid food spoilage.

Control of Insects

Insects destroy almost 50 percent of the annual cereal grain crops in some developing countries. Traditionally, food industry has controlled insect pests in grains and some dried food by fumigation (process in which fumes of chemicals are used to kill insets). Such chemicals are used which give maximum insect control and minimum health hazard(damage).These food are further protected from insects by packaging in insect proof containers.

Control of Rodents

Complete removal of rodents is almost impossible. The situation is worse in developing countries. Systematic control of rat and mice is practiced in most of the industrial units of developed countries. A typical systematic control includes the use of poison baits, rat-traps and biological method ( use of Cats ) to kill rat and mice.

Control of Birds

Birds consume grains in the field before crop is harvested. This loss by birds has traditionally been reduced by installing noise-making dummies ( shaped like humans or animals ) at different points in the farm. Birds also contaminate(add impurities) food and water. To prevent this, bird screens can be used over grain or water storage.

Food Preservation - Principle 2

Prevention or Delay of Bacterial Activity {Principle 2}

As it is told in principle 2 of food preservation that by keep in microorganisms e.g bacteria out of food is helpful in the preservation of food.

How this can be done?

Firstly, precautions may be taken to prevent their entry in the food, but where they have already gained access,these may be thrown out.

Keeping microorganisms out

Nature creates all foods free from microorganisms and provides a protective covering to prevent their entry inside the food. Orange, Banana, Mango, Wheat, Maize, Rice and Groundnut etc. are all free free from microorganisms when produced. The skin, peel,husk and shell provide protection to food from the entry of bacteria and other microorganisms. So far as these bacteria are not allowed to enter the food, our food is preserved and cannot be spoiled.

Creation of Unfavourable Conditions

Such conditions are provided to food in storage which are not favourable for the growth of microorganisms. Canning is commercially done to prevent the entry of bacteria into the food. In canning, food is packed inside tin cans.

Temperature is yet another very effective tool in the hands of people engaged in food preservation to create unfavourable conditions.

Food Preservation - Principle 1

Prevention and Delay of Autolysis {Principle 1}

It is told in principle 1 of food preservation that autolysis (process in which food is spoiled by enzymes) can be prevented by destruction of enzymes. How we can destroy enzymes? We can do this by treatment of food with high temperature, low temperature and removal of moisture from food.

Treatment with high temperature

Some fruits and most of the vegetables are normally subjected to around 100 degree centigrade for a few minutes. As a result of this exposure to high temperature,most of the damaging enzymes are destroyed. High temperature physically kills the enzymes.

Treatment with Low Temperature

In this treatment food is subjected to low temperature. This low temperature effect the growth of enzyme but slow down their growth. As the growth of enzyme is slow down they cannot spoil the food. Refrigerators and cold storage are used for this purpose.

Removal of moisture

Enzyme require moisture for their activity. If moisture is not available , they cannot perform their function and food is preserved. The moisture in food is removed by sun drying, dehydration(removal of water from food) and evaporation(removal of moisture in the form of vapours).

How to Create XmlHttpRequest Object

It's a bit difficult .
Because each and every browser vendor implemented this XmlHttpReuest object in their own style.
if we take a look at this XmlHttpRequest object implmentation there are two types one is Microsofts Approach is in the form ActiveXObject.
Good what about browsers that doesn't support ActivexObjects .
Browsers like Firefox,Mozilla,Opera,Safari... etc implemented this XmlHttpRequest object as Built in Javascript object.
Note: in Internet Explorer 5.5 version XmlHttpRequest is implement in "MICROSOFT.XMLHTTP" and in version 6.0 it is "MSXML2.XMLHTTP".
we can create XmlHttpRequest object using a try catch block or If Else structure now we will see both of them.
First:
Using Try Catch
function createXmlHttpRequestfun()
{
var XmlHttp=null;
try{
XmlHttp=new XmlHttpRequest(); // for opera,firefox,safari... etc
}
catch() //if it fails it must be interent explorer
{
try
{
XmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); // check whether it is a IE 5.5
}
catch
{
XmlHttp=new ActiveXObject("Msxml2.XMLHTTP"); // check whether it is a IE 6.0
}
}
if(XmlHttp==null)
{
alert("Browser Doesn't support Ajax");
return null;
}
else
return XmlHttp;
}

2)
Now Using If Else
function createXmlHttpRequestfun()
{
var XmlHttp=null;
if(window.XMLHttpRequest) //Checking whether it is a firefox,opera...
{
XmlHttp= new XMLHttpRequest();
}
else if(window.ActiveXObject)//Checking whether it is a IE or not
{
XmlHttp= new ActiveXObject("Microsoft.XMLHTTP"); //for IE 5.5
if(XmlHttp==null)
XmlHttp= new ActiveXObject("Msxml2.XMLHTTP"); //for IE 6.0
}
if(XmlHttp==null)
{
alert("Browser Doesn't support Ajax");
return null;
}
else
return XmlHttp;
}

What is Ajax??

Well First of all before going to learn about ajax we must know what ajax stands for........
Ajax shortly stands for "Asynchronous javascript and xml"
Ajax is there from the very beginning but made popular by Google....
Ajax is not a new technology not even a new programming language it is just a new way of using existing standards and technologies.
to do Ajax programming one must know the following...
1)HTML (mostly we use div and span tags)
2)CSS (Optional)
3)JavaScript
4)XML(Optional)
Ajax : It is a way of sending HTTP Requests to web server from JavaScript Using "XmlHttpRequest" Object .
Think about web whith out Ajax what are the other ways of sending request from web page .
1)By Clicking HyperLink Tag.
2)Clicking Submit Button.
For this kinds of requests we will see a new page will be loaded.
What if we want to load new things in to a page that was already loaded in to the browser. Here the Ajax comes in to play.
Using Ajax it is Possible to send requests to webserver from webpage in background means user will not aware of this requests.The response that comes from webserver will be inserted in to the existing (already loaded) page using javascript and html span and div tags.
Basically sending and receiving requests to and from server are handled by "XmlHttpRequest" Object .

Note:In Ajax we will never see a new page is going to loaded(No page refresh) all the things are going to happen in a single page.Simple i can say it works like a stand alone application. Most importantly browsers back button doesn't work.

Tips for Building a great blog

1:Before Starting to build a popular blog

Before starting a blog you must think , Is "Blogging is right for you". There are any factors you should consider for this and it is the first step for becoming a successful blogger. The factors include:

a}Become a good surfer of internet

A good blogger will surf the internet. you should do the same so that you can view other blogs,websites and you will know how to write articles and how to attract visitors to become your blog subscribers

b}Teach yourself to improve english skills

Learn how to write the posts to attract visitors.

2:Choosing a right Blogging software

There are many blogging softwares, Some are free and some cost you.You should choose which one best suites your need. Choose from one of the softwares:

a}wordpress:

If you want a free blog, you can get it from wordpress.They will give you hosting and a subdomain like www.yourname.wordpress.com .. But you cannot place advertaising on this free blog, you can't upload new plugins or themes,widgets.
If you want all these features, then you should buy webspace and install wordpress software which is free and is available at www.wordpress.org .

b}Blogger:

Blogger is a free software and easy to write posts in it.Many websites are offering free blogger templates and you can choose from them.You are given many widgets in blogger.Easy to use all of them. You can also include your domain name than using www.yourname.blogspot.com .You can also place google adsense advertaising ads directly.

c}Typepad

Unlike other blogging software TypePad is not free.You have to pay money for using it and they provide the hosting for your blog.

d}MovableType

Summary

You can choose blogger if you want free blog with all features. If you want great blogging experiance and you can spend money for hosting and domain, then choose worpress although free wordpress is there only you can express feelings in your blog not more than that

Principles of Food Preservation

Spoilage agents(bacteria, fungi etc) cause damage to food.These should be stopped to preserve food. There are different principles to check the activities of these agent and preserve food.

Note:-We have only explained you the concept of food preservation in this post, we will explain each principle in upcoming posts.

Principle 1

Autolysis (process in which food is spoiled by enzymes) in food may be stopped or delayed by destroying enzymes and by the treatment and handing of food in such a manner so as to stop the reactivity of chemically active molecules.

Principle 2

Spoilage in food as a result of activity of bacteria may be preserved or delayed by either stopping the entry of microorganisms into the food, physically removing them from the food, hindering (reducing) their growth and activity or even destroying them, if they are already present in the food.

Principle 3

Quality defects and losses in food caused by insects, rodents and birds may be controlled by proper packaging and by instituting a sustained (controlled) population control programme of such pests.

Principle 4

The deterioration in food caused by the physical phenomenon occurring during processing,handling and storage may be reduced by the development of optimal(best) handling, processing and storage conditions.

Blogging tips and tricks every blogger should know

Blogging Tips,Tricks a blogger should know to become a Top Blogger

Either if you are a serious blogger or writing posts for fun, you should follow these tips, tricks and hints to achieve your feet in blogging . If you follow these blogging hints you will definitely enhance your blogs design, readability and increase earning potential of your blog .
Now infinite blogs are evolving and when i go through some blogs, I find very uneasy reading their blogs and they even don't get their website listed in search engines with good rank even if they website age is old. So, don't fall into this category of blogger. Every blogger want to increase their blog in search engine listings and get quality traffic to their blog, So that they can earn more money. If you are a blogger you are thinking like this, Isn't it.
I will start from building your blog and continue to the topics like search engine listings, Search engine optimization, driving traffic to your blog, Monetize your blog.
The important steps you have to follow:

• Building blog


• Writing posts


• Search Engine Optimization


• Driving traffic




• Using Digg to drive traffic to your website


• Increasing your blog's subscribers


• Listing your blog in Blog Directories


• Participating in Blog Contests


• Participating in Forums




• monetize your blog

I have explained about each topic in next chapters.