Website, Webpage & Types

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Web Server, Hosting of a Website

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Browser, Add-Ons & Plugins, Cookies

XII – IP – COMPUTER NETWORKS

Website :

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Each one of us might have visited one or the other website. A website in general contains information organised in multiple pages about an organisation. A website can also be created for a particular purpose, theme or to provide a service.

A website (usually referred to as a site in short) is a collection of web pages related through hyperlinks, and saved on a web server. A visitor navigates from one page to another by clicking on hyperlinks. Also, all the pages of a website are integrated under one domain name and have a common theme and template.

For example, the website of NCERT will have all the pages related to NCERT, viz., textbooks, syllabus, events, resource materials, etc., under one domain name and having a common design theme.

To access a website, one has to type the address of the website (URL) in the address bar of a browser, and press enter. The home page of the website will be displayed.

Purpose of a Website :

We are living in an Internet era where the whole world is connected. A website’s purpose is to make the information available to people at large. For example, a company might like to advertise or sell its products, a government organisation may like to publish circulars, float tenders, invite applications or get feedback from various stakeholders.

A website is a means that helps to communicate with people in a specific, transparent and user friendly manner. Therefore, while developing a website, the first question to ask is why the website is being created, and what should be its pages so that it serves the required purpose.

Basically, a website should be user friendly and provide information to users with minimum efforts. A website should be designed keeping in mind different categories of people that will be visiting the site.

Some of the common purposes for which websites are designed are listed below:

• Selling products and delivering services

• Posting and finding information on the internet

• Communicating with each other

• Entertainment purposes

• Disseminating contents and software

Web Page:

A web page (also referred to as a page) is a document on the WWW that is viewed in a web browser. Basic structure of a web page is created using HTML (HyperText Markup Language) and CSS (Cascaded Style Sheet).

A web page is usually a part of a website and may contain information in different forms, such as:

● text in the form of paragraphs, lists, tables, etc. ● images ● audio ● video

● software application ● other interactive contents

Additionally, various styling and formatting are applied on a web page to make it attractive and organised. Further, program codes called scripts are used to define the manner in which the page will behave on different actions. Scripts make a web page interactive. JavaScript is the most popular and commonly used scripting language. However, Python and PHP are also used to apply scripting on a web page.

The first page of the website is called a home page. It generally contains information and links to all the related web pages. Each web page has a unique address that is visible on the address bar. Hence if we want to view a particular web page, its address has to be typed in the address bar of the browser. The web pages that are linked to form a website share a unique domain name.

For example, https://swayam.gov.in/ is a website by the Government of India to deliver online courses for School, College and University students and teachers. It is a collection of multiple web pages that link to different courses related information.

Static and Dynamic Web Pages

A web page can be static or dynamic. A static webpage is one whose content always remains static, i.e., does not change for person to person. When a web server receives a request (from browser) for a static web page, it just locates the page on its storage media and sends it to the browser of the client. No additional processing is performed on the page.

Hence, a static web page remains the same for all users until someone changes its code manually. Static web pages are generally written in HTML, JavaScript and/or CSS and have the extension .htm or .html.

Working of a static web page

On the other hand, a dynamic web page is one in which the content of the web page can be different for different users. The difference in content may be because of different choices made by the user. When a request for a dynamic web page is made to the web server, it does not simply retrieve the page and send.

Before sending the requested web page, the server may perform some additional processes like getting information from the database, updating date and time, updating weather information, etc. The content of such pages changes frequently. They are more complex and thus take more time to load than static web pages.

Dynamic web pages can be created using various languages such as JavaScript, PHP, ASP.NET, Python, Java, Ruby, etc. These are complex to construct and design, as the code to perform the additional operations has to be added. Such server side code allows the server to change its content each time the page is loaded.

Further, most dynamic pages are linked to databases so that each time the page is uploaded, the required information from the databases is retrieved to update the web page. Few common examples of dynamic web pages are those web pages displaying the date, time, and weather report or having e-commerce applications.

Working of a dynamic web page

Web Server :

A web server is used to store and deliver the contents of a website to clients such as a browser that request it. A web server can be software or hardware. When talking about a web server as computer hardware, it stores web server software and a website's contents (HTML pages, images, CSS stylesheets, and JavaScript files).

The server needs to be connected to the Internet so that its contents can be made accessible to others. When talking about a web server as a software, it is a specialised program that understands URLs or web addresses coming as requests from browsers, and responds to those requests. The server is assigned a unique domain name so that it can be accessed from anywhere using the domain name.

To develop and test a website using a personal computer, we need to first install a web server on that computer. The web browser from the client computer sends a request (HTTP request) for a page containing the desired data or service. The web server then accepts, interprets, searches and responds (HTTP response) to the request made by the web browser. The requested web page is then displayed in the browser of the client. If the server is not able to locate the page, it sends a page containing the error message (Error 404 – page not found) to the client’s browser.

Hosting of a Website :

Web hosting is a service that allows us to put a website or a web page onto the Internet, and make it a part of the World Wide Web. Once a website is created using a hardware server, we need to connect it to the Internet so that users across the globe can access. On the other hand, we can rent server resources (CPU, RAM, and storage) from a cloud service provider and host our locally created website there. This is done by uploading the files constituting the website (HTML, CSS, JavaScript, images, databases, etc.) from the local computer onto the space allocated on the server. For this, we have to avail the services of a web hosting service provider. These services for using the server’s resources such as RAM, hard disk, bandwidth, etc., are usually paid and these resources can be increased or decreased as per the loads on the website.

A web server whether it is a local server or a cloud server when connected to the Internet is assigned a unique numeric address on the Internet called IP address. This IP address needs to be mapped to a textual name called domain name of the website. This is because it is not convenient for users to remember a numeric IP address.

Thus, for accessing a website, the user enters the domain through a browser (URL). The domain name has to be registered (purchased) with an authorised agency.

How to host a website?

To host a website, follow the steps given below:

• Select the web hosting service provider that will provide the web server space as well as related technologies and services such as database, bandwidth, data backup, firewall support, email service, etc. This has to be done keeping in mind the features and services

that we want to offer through our website.

• Identify a domain name, which best suits our requirement, and get it registered through domain name Registrar.

• Once we get web space, create logins with appropriate

rights and note down IP address to manage web space.

• Upload the files in properly organised folders on the allocated space.

• Get domain name mapped to the IP address of the web server.

The domain name system (DNS) is a service that does the mapping between domain name and IP address. When the address of a website is entered in a browser, the DNS finds out the IP address of the server corresponding to the requested domain name and sends the request to that server.

Web Browsers: Introduction, commonly used browsers, browser settings, add-ons and plug-ins, cookies.

Browser :

A browser is a software application that helps us to view the web page(s). In other words, it helps us to view the data or information that is retrieved from various web servers on the Internet. Some of the commonly used web browsers are Google Chrome, Internet Explorer, Mozilla Firefox, Opera, etc.

A web browser essentially displays the HTML documents which may include text, images, audio, video and hyperlinks that help to navigate from one web page to another.

The initial web browsers like Mosaic used to support HTML documents containing plain text (static website) only, but nowadays with the advancement of technology, modern web browsers allow us to view interactive and dynamic websites.

In addition to this, most modern browsers allow a wide range of visual effects, use encryption for advanced security and also have cookies that can store the browser settings and data.

Browser Settings:

Every web browser has got certain settings that define the manner in which the browser will behave. These settings may be with respect to privacy, search engine preferences, download options, auto signature, autofill and autocomplete feature, theme and much more.

Each browser application allows us to change or customise its settings in a user friendly manner.

Change the browser settings using the open source browser, Mozilla Firefox :

Open Mozilla Firefox, and on the top right corner of the browser window, click the Menu button.

Mozilla Firefox Menu button

From the drop down button, select Options. The preferences and Options window will be displayed in the browser.

On the left side, there are multiple Panels to choose from: General, Home, Search, Privacy and Security and Sync.

General Panel: Some of the options that the panel contains are as follows:

• setting the default browser

• language and appearance of text

• downloading files and applications

• firefox update settings

• browsing and network settings

Home Panel: This panel contains options to set the home page of the browser, browser window and tab settings.

Search Panel: This panel contains options to edit the settings of the search engine used by Firefox.

Privacy and Security Panel: This panel contains options to secure the browser and data. It includes the following:

• enhanced tracking protection

• forms and passwords

• history and address bar

• cookies and site data

•permission to view pop ups windows and install addons

Sync Panel: This panel contains options to set up and manage a Firefox account which is needed to access all services given by Mozilla. Make the desired settings and close the browser settings window. The changes made in the browser settings will be applied.

Add-Ons and Plug-ins

Add-ons and plug-ins are the tools that help to extend and modify the functionality of the browser. Both the tools boost the performance of the browser, but are different from each other.

A Flash player is required to play a video in the browser.

Add-ons and plug-ins

To add an extension, click the Options button on the top right corner of the browser and select the Addons option. Click the Extensions Panel option on the left. On the right, options to Manage your Extensions will appear. There will be a list of enabled, disabled and recommended extensions. Make the desired selections and close the add-ons window.

Similarly, to add plug-ins, click Plug-ins options on the left side of the browser window. Make the desired selections to enable or disable the required plug-ins. 

Cookies:

A cookie is a text file, containing a string of information, which is transferred by the website to the browser when we browse it. This string of information gets stored in the form of a text file in the browser.

The information stored is retransmitted to the server to recognise the user, by identifying pages that were visited, choices that were made while browsing various menu(s) on a particular website.

It helps in customising the information that will be displayed, for example the choice of language for browsing, allowing the user to auto login, remembering the shopping preference, displaying advertisements of one’s interest, etc.

Cookies are usually harmless and they can’t access information from the hard disk of a user or transmit virus or malware. It is the browser on our computer which stores and manages the cookies.

However, viruses can also be tricked as cookies and cause harm to a computer. One can disable cookies by changing the Privacy and Security settings of our browser.

SUMMARY

• A group of two or more similar things or people interconnected with each other is called network

• A computer network is an interconnection among two or more computers to share data and resources.

• Devices in a network can be connected either through wired or wireless media.

• Based on the geographical area covered and data transfer rate, computer networks are broadly categorised as LAN, MAN and WAN.

• The protocol or the set of rules that decide functioning of a LAN is called Ethernet.

• Local Area Network (LAN) is a network that connects digital devices placed at a limited distance of upto 1 km.

• Metropolitan Area Network (MAN) is an extended form of LAN which covers a larger geographical area like a city or a town.

• Wide Area Network (WAN) connects computers and other LANs and MANs, which are spread across different geographical locations of a country or in different countries or continents.

• A repeater is an electronic device that receives a weak signal and regenerates it.

• Modem (MOdulator DEMolulator) refers to any such device used for conversion between analog signals and digital bits.

• A hub is a network device used to connect multiple devices to form a network or to connect segment(s) of LAN.

• A switch is a networking device that filters network traffic while connecting multiple computers or communicating devices.

• A router is a network device that can receive the data, analyse it and transmit to other networks.

• A gateway is a device that connects the organisation’s network with the outside world of the Internet.

• The physical organisation of computers, cables and other peripherals in a network is called its topology. Common network topologies are Bus, Star, Tree, Mesh, etc.

• In bus topology, each communicating device connects to a common central transmission medium, known as bus.

• In star topology, each communicating device is connected to a central node, which is a networking device like a hub or a switch, through separate cables.

• In tree topology, multiple star and bus topologies are connected to a central cable, also called the backbone of the network.

• In mesh topology, each communicating device is connected with every other device in the network.

• The Internet is the largest WAN that connects millions of computers across the globe.

• Some of the services provided through the Internet are information sharing, communication, data transfer, social networking, e-commerce, etc.

• A Uniform Resource Locator (URL) is a standard naming convention used for accessing resources over the Internet.

• Electronic mail is a means of sending and receiving message(s) through the Internet.

• Chatting is communicating in real time using text message(s).

• Voice over Internet Protocol (VoIP) allows you to have voice calls over digital networks.

• A website is a collection of related web pages.

• A web page is a document that is viewed in a web browser such as Google Chrome, Mozilla Firefox, Opera, Internet Explorer, etc. It can be static or dynamic.

• A static web page is one whose content does not change for requests made by different people.

• A dynamic web page is one in which the content of the web page displayed is different for different users.

• A web server is a program or a computer that provides services to other programs or computers called clients.

• Web hosting is a service that allows you to post the website created locally so that it is available for all internet users across the globe.

• Every browser has got certain settings that define the manner in which the browser will behave. These settings may be with respect to privacy, search engine preferences, download options, auto signature, autofill and autocomplete feature and much more.

• Add-ons and plug-ins are the tools that help to extend and modify the functionality of the browser.

• A cookie is a text file containing a string of information which stores browsing information on the hard disk of your computer.