Table of Contents

It is the part of internet known as Web. It is a collection of websites or webpages stored in web servers and connected to local computers through internet.


These websites contain text pages, digital images, audio, video etc. Users can access the content of these sites from any part of the world over the internet by using devices such as computers, laptops, cell phones etc.


WWW, along with internet, enables the retrieval and display of the text and media to our device.


The building blocks of the web are web pages, which are formatted in HTML and connected by links called “Hyper Text” or “Hyper Links” and accessed by HTTP.

These links are electronic connections that link related pieces of information so that users can access the desired information quickly.


Hypertext offers the advantage to select a word or phrase from text and thus to access other pages that provides additional information.


URL (Uniform Resource Locator) –

  1. Each webpage is assigned a unique online address known as URL.
  2. A website consists of a collection of webpages all belonging to a specific URL.
  3. Examples include: www.facebook.com, www.google.com.


Web Browsers:

A web browser is a software program that allows a user to locate, access, and display web pages. In common usage, a web browser is usually shortened to "browser." Browsers are used primarily for displaying and accessing websites on the internet, as well as other content created using languages such as Hypertext Markup Language (HTML) and Extensible Markup Language (XML).


Browsers translate web pages and websites delivered using Hypertext Transfer Protocol (HTTP) into human-readable content. They also have the ability to display other protocols and prefixes, such as secure HTTP (HTTPS), File Transfer Protocol (FTP), email handling (mailto:), and files (file:).


In addition, most browsers also support external plug-ins required to display active content, such as in-page video, audio and game.


Top Web Browsers –

List of top web browsers include: -


1. Google Chrome –

It is a popular Browser by Internet giant Google. Focuses on enhanced performance of web applications. Hundreds of useful extensions can be downloaded for free from Chrome Store and can be used for personal use.


A large array of apps and add ons available at Chrome Store. These adds a considerable amount to the browsing experience of the users.

  1. Private browsing
  2. Fast Startup
  3. Phishing/Malware Filter


2. Mozilla Firefox –

A web browser designed for simplicity, security, extensibility yet flexibility and power.

Available for Linux and android as well. There are lots of plugins and extensions with some powerful developer tools.

Constant updates, high performance delivered and customizable interface is a bliss for advanced users. Firefox allows an open architecture which accepts the installation of themes and extensions. Themes give the browser a customizable new look. Developers can write extensions to make the browser perform functions as desired like check your Gmail account when you open the browser, or block all ads.

It supports:

  1. RSS Headlines
  2. Chat Extensions
  3. Spam/ Malware Filter


3. Opera Web Browser –

Constantly evolving and improving and the most popular mobile browser, opera has come a long way from being a browser to a full-fledged internet suite.

It provides fast browsing with good support for updates. Features like page zoom and developer shortcuts allow users to have unique experience. There are some compatibility issues found in certain websites but with constant updates these problems are scarce.

It includes:

  1. Email suite
  2. Phishing Filter
  3. Bit Torrent


4. Safari Web Browser –

Safari is a web browser developed by Apple inc. It is the most popular browser with MAC users.

It is known for its clean and fast browsing experience and is based on the WebKit rendering engine. Safari offers features like tabbed browsing, popup blocking and built-in search functionality. It also has one of the best RSS-reading feature available online, it is easier to keep track a number of websites than using bookmarks.

It is the most Popular Macintosh Browser. Supports private browsing and bookmark import from other browsers.


5. Internet Explorer –

Internet Explorer by Microsoft is the default browser for Windows operating system. It is still very popular with many internet users. Startup speed is a big issue with internet explorer.

There are a lot of necessary features like Active X capabilities, SmartScreen Filters, a list of recommended sites and more. Internet Explorer is still considered to be falling behind in the race, but latest editions promise fast load, packed with latest features.

It supports:

  1. Add ons
  2. Customization options
  3. Mouse Gestures


6. Slimjet Browser –

Slimjet is a powerful and one of the best browsers around. It has in built extensions to ease internet browsing. Powered by Blink Engine, Slimjet supports all Chrome Apps plus a bundle of more extensive built in apps.

Slimjet is as good as Chrome, has powerful and customizable interface like Firefox, reliability features and in built apps which load a power packed browser every time you use it.

Features include:

  1. Ad blocker & Download Manager
  2. Social Sharing and YouTube Downloader
  3. Faster, Secure and Reliable


7. Maxthon –

A fast browser with a lot of features and reliable user interface. Powered by Maxthon Cloud Engine, it offers seamless browsing and downloads. It works on all platforms.

Maxthon has lots of nifty features, including video-ad fast-forwarding, speedy performance and Two-page rendering engines (Webkit and Trident) for better compatibility.

It includes:

  1. Anti-Spyware
  2. Pop up Blocker
  3. Cloud Browsing


8. Slim Browser –

A popular choice for users who like speed and security. It is based on Internet Explorer's

Trident Engine and is a robust and powerful browser. It flaunts better usability features and speed compared to internet explorer browser.

Slim browser takes care of your privacy and security every time you are surfing online. It starts as quickly as possible and allows you to have an amazing web surfing experience.

Its features include:

  1. Omni Bar mode
  2. Integrated Plugins (Ad Blocker, Photo Salon)
  3. Low Crash and Bugs


9. Netscape Browser –

Originally published by the Netscape Communications Corporation, Netscape browser has released latest version based on Mozilla Firefox. It is fast, secure and is a choice of many users online.

It features:

  1. Dynamic HTML
  2. Integrated Search Engine
  3. Open source Development


10. UC Browser –

A popular browser for both desktop and mobile devices. Tabbed browsing and fast startup make it a popular choice for thousands of users. It is known for its efficient download management and supports full screen browsing.

Features include:

  1. Quick browsing
  2. Quick Page sharing
  3. Multiple Apps


Domain Name System:


Domain Name Servers (DNS) are the Internet's equivalent of a phone book. They maintain a directory of domain names and translate them to Internet Protocol (IP) addresses. This is necessary because, although domain names are easy for people to remember, computers or machines, access websites based on IP addresses.

A domain name is your website name. It is the address where Internet users can access your website.


The domain name system maps the name people use to locate a website to the IP address that a computer uses to locate a website.

For example, if someone types example.com into a web browser, a server behind the scenes will map that name to the corresponding IP address, something similar in structure to 121.12.12.121.


Web browsing and most other internet activities rely on DNS to quickly provide the information necessary to connect users to remote hosts. DNS mapping is distributed throughout the internet in a hierarchy of authority. Access providers and enterprises, as well as governments, universities and other organizations, typically have their own assigned ranges of IP addresses and an assigned domain name. They also typically run DNS servers to manage the mapping of those names to those addresses. Most URLs are built around the domain name of the web server that takes client requests.


How DNS works?

A Domain Name System (DNS) works in the following way: -


1. DNS servers handle request from both inside and outside their domain.


2. When a server receives a request for information about a name or address within its domain, it provides the authoritative answer.


3. For requests outside its domain, it forwards the request to another server, often managed by ISP.


4. If that server doesn’t have the answer, it queries the DNS server for the top-level domain (For eg.: .com) and eventually the authoritative server for the specific domain.


5. The answer flows back along the same path.


DNS Structure:

A domain name is made of multiple parts, called labels. The domain hierarchy is read from right to left with each section denoting a subdivision. The top-level domain is what appears after the period in the domain name. A few examples of top-level domains are .com, .org and .edu, but there are many others that can be used. Some may denote a country code or geographic location such as .us for the United States or .ca for Canada.


Some Top-level domains include –

  1. .com – commercial
  2. .org – organisation
  3. .net – network
  4. .int – international organisations
  5. .edu – education
  6. .gov – government
  7. .mil – military


Country code or geographical location –

  1. .in – India
  2. .us – United States of America
  3. .jp – Japan
  4. .uk – Unite Kingdom
  5. .ca – Canada
  6. .cn – China
  7. .iq – Iraq


IP Address:

An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.

An IP address serves two main functions:

  1. host or network interface identification, and
  2. location addressing.

An IP address is written in "dotted decimal" notation, which is 4 sets of numbers separated by period each set representing 8-bit number ranging from (0-255).

An example of IPv4 address is 216.3.128.12, which is the IP address previously assigned to iplocation.net.


Protocol:

A protocol is a set of rules and guidelines for communicating data. Rules are defined for each step and process during communication between two or more computers. It is a digital language through which we communicate with others on the Internet. They ensure proper information exchange between devices.

Each protocol is defined in different terms and different use with unique name. Message travel from sender to reciever via a medium (The medium is the physical path over which a message travels) using a protocol.


Types of Protocol –

Types of Protocol include: -


1. TCP (Transmission Control Protocol) –

It is used for communication over a network. In TCP data is broken down into small packets and then sent to the destination. However, IP is making sure packets are transmitted to the right address.


2. IP (Internet Protocol) –

It works in conjunction with TCP. It is an addressing protocol that routes and delivers packets to the destination. The IP protocol was developed in 1970s.


3. UDP (User Datagram Protocol) –

An alternative communications protocol to Transmission Control Protocol (TCP) used primarily for establishing low-latency and loss-tolerating connections between applications on the internet.


4. FTP (File Transfer Protocol) –

File transfer protocol is basically used for transferring files to different networks. There may be a mass of files such as text files, multimedia files, etc. This way of file transfer is quicker than other methods.


5. SMTP (Simple Mail Transfer Protocol) –

Simple mail transfer protocol manages the transmission and outgoing mail over the internet.


6. HTTP (Hyper Text Transfer Protocol) –

HTTP is based on client and server model. It is used for making a connection between the web client and web server. HTTP shows information in web pages.


7. Ethernet –

Ethernet is most important for LAN communication. It transmits the data in digital packets. If any computer wants to use this protocol they should contain Ethernet Network Interface Card (NIC). The card is implemented with unique address code fixed in the microchip.


8. Telnet –

Telnet is mainly used for the remote login process. The computer which is requesting for a connection, is a local computer and which is accepting the connection, is a remote computer. If you give a command in a local computer, that command is executed in the remote computer. Telnet based on client and server model.


9. Gopher –

Gopher is an application layer protocol, which is used for searching and retrieving documents from remote sites.


TCP/IP:

TCP/IP, or the Transmission Control Protocol/Internet Protocol, is a suite of communication protocols used to interconnect network devices on the internet. TCP/IP can also be used as a communications protocol in a private network (an intranet or an extranet).


TCP/IP specifies how data is exchanged over the internet by providing end-to-end communications that identify how it should be broken into packets, addressed, transmitted, routed and received at the destination. TCP/IP requires little central management, and it is designed to make networks reliable, with the ability to recover automatically from the failure of any device on the network.


The two main protocols in the internet protocol suite serve specific functions.

  1. TCP defines how applications can create channels of communication across a network. It also manages how a message is assembled into smaller packets before they are then transmitted over the internet and reassembled in the right order at the destination address.
  2. IP defines how to address and route each packet to make sure it reaches the right destination. Each gateway computer on the network checks this IP address to determine where to forward the message.


How TCP/IP works?

TCP/IP uses the client/server model of communication in which a user or machine (a client) is provided a service (like sending a webpage) by another computer (a server) in the network.


Collectively, the TCP/IP suite of protocols is classified as stateless, which means each client request is considered new because it is unrelated to previous requests. Being stateless frees up network paths so they can be used continuously.


The transport layer itself, however, is stateful. It transmits a single message, and its connection remains in place until all the packets in a message have been received and reassembled at the destination.


The TCP/IP model differs slightly from the seven-layer Open Systems Interconnection (OSI) networking model designed after it, which defines how applications can communicate over a network.