HTML(Hypertext Markup Language)

HTML is the language that helps in creating and designing web content. It is a markup language. It has a
collection of tags and attributes for defining the layout and structure of the web page. A HTML document has the extension .htm or .html.

XML (EXtensible Markup Language)

XML is a markup language like HTML. It is designed to carry or store data. Unlike HTML, it does not have predefined tags. It is possible to define new tags
in XML.

WWW (World Wide Web) 

The World Wide Web was invented by a British scientist, Tim Berners-Lee in 1989. World Wide Web, which is also known as a Web, is the universe of the information available on the internet. It is a collection of websites or web pages stored in web servers and connected to local computers through the internet. These websites contain text pages, digital images, audios, videos, etc. Users can access the content of these sites from any part of the world over the internet using their devices such as computers, laptops, cell phones, etc.

Web page 

A web page is an electronic document designed using HTML. It displays information in textual or graphical form. It may also contain downloadable data files, audio files, or video files. Traversal from one webpage to another web page is possible through hyperlinks. 

A web page can be classified into two types:

1. Static web page: A web page that displays the same kind of information whenever a user visits it, is known as a Static web page.
   
   
2. Dynamic web page: A web page that displays different information each time whenever a user visits it, is known as Dynamic web page.

 Website

A collection of web pages that are accessible through a single domain known as a website. A website has multiple webpages providing information about a particular entity.

Web Browser

A web browser is a software program to navigate the web pages on the internet. A browser interprets the coding language of the web page and displays it in graphic form. A web browser allows anyone to access the web without even knowing commands used in software languages to design a web page.  

Internet works on the client-server model. A web browser is a client that requests the information from the web server. The web server sends the information back to the client. The web address of the webpage written on the address bar tells the web browser which page to access.

Web Server

A web server is a WWW server that responds to the requests made by web browsers/clients.

URL (Uniform resource locator) 

The web address of the web page written on the address bar of the browser is known as the uniform resource locator (URL). A URL is a formatted text string used to identify a network resource on the Internet.
Network resources are files that can be plain Web pages, text documents, graphics, downloadable files,
services, or programs. Every network resource on the web has a unique URL. 

Domain Name  

A server identified by a set of characters known as Domain name. It is an address part of any URL from which we access all resources available on that server.

Web Hosting

Web hosting is the process of uploading/saving the web content on a web server to make it available on
WWW. In case an individual or a company wants to make its website available on the internet, it should be hosted on a web server.

 

Wi-Fi

Wi-Fi is a wireless networking technology that allows computers to connect with the internet without using direct lines or cable from our PC to the Internet. For working of wi-fi we need-

1. Internet Connection
2. Wireless Router
3. Computers having a wireless network card.

Wi-Fi Hotspot

Wi-Fi is a venue or place that provides Wi-Fi access. These locations can be School campus, Restaurant, Library, Railay station, etc where the public can use a laptop, Mobile phone, or another suitable device to access Wi-Fi.

WiMax

WiMax is a wireless digital communication system. WiMax can provide broadband wireless access up to 30 miles (50 KM) for fixed stations. WiMax requires a  tower called base station similar to a cell phone tower. WiMax is more secure, can cover more area, and can provide more internet speed than a Wi-Fi.

VOIP

VOIP stands for Voice over Internet Protocol. VOIP provides phone services over the internet. It is more reliable and cheaper than traditional phone services.

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1G mobile system

The 1G mobile system is introduced in the early 1980s. The 1G mobile system was based on analog cellular Technology. This network was mainly designed for voice calls no consideration of Data Services. The major drawback of the 1G system were its low capacity, poor voice links and no security.

2G mobile system

The 2G network was the first digital cellular system introduced in 1990. The 2G system was based on GSM Technology. 2G was offering improved sound quality, better security, SMS, Voicemail and fax services.

2.5G mobile system

 It is the enhanced version of 2G. It offers services like MMS, sending pictures through email.

3G mobile system

3G Technology adds multimedia facilities to the 2G phone by allowing video, audio and graphics applications. With the invention of 3G watching online videos and video conferencing become a reality. It has the capacity of higher data rates and it opens the door to many internet style applications. The 3G mobile system is also known as the universal mobile telecommunication system (UMTS).

4G mobile system

4G is an enhanced version of 3G it is based on packet switching. It is able to support faster transmission. It provides data rate up to 100 MBPS. It is wireless access technology.

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Types of Computer Network

A computer network means a group of networked computers. A network can be a small group of linked computers or can be a large group. Thus networks vary in size and complexity.  There can be four types of networks on the basis of geographical spread.

1. Personal area network (PAN)
2. Local area network (LAN)
3. Metropolitan area network (MAN)
4. Wide area network (WAN)

Personal area network (PAN)

A personal area network organized around an individual person, typically within a 10-metre range. For example- a person has a laptop, mobile phone, PDA and any portable printer all are connected with a single Wi-Fi network.

Local area network (LAN)

A local area network is a computer network that interconnects computer within a limited area such as Residency, School, laboratory, University campus, or office building.  The key purpose of a LAN  is to serve its user in resource sharing. The hardware, as well as software resources, are shared through LANs.

Metropolitan area network (MAN)

Metropolitan Area Network is the networks spread over a city.  For example -  cable TV Network that is spread over a city. It is just a bigger version of LAN and normally uses similar Technology. MAN is also the sharing of hardware and software resources along with its user.

Wide area network (WAN)

The network spread across the large geographical area like countries are known as wide area networks. A wide area network is a group of LANs that are spread across several locations and connected together to look like one big LAN.  Wide area network link offers computer to exchange information at laser costs and higher speeds. The internet is the largest WAN,  spanning the entire Earth.