i) HTTP - Hypertext Transfer Protocol
ii) HTTPS - Hypertext Transfer Protocol Secure
iii) FTP - File Transfer Protocol

(i) It provides mobility.
(ii) It provides connection to Internet.
(iii) Flexibility of LAN.
(iv) Ensures connectivity.
(v) Low cost, high benefits.

Intranet is a private network within an enterprise to share company data and computing resources between the employees. It may consist of many interlinked local area networks.

(i) UDP- User Datagram Protocol
(ii) DNS - Domain Name System
(iii) OSI – Open System Interconnection
(iv) RFID- Radio Frequency Identification

(i) HTTP: A protocol used between a web client and a web server protects non-secure data transmissions. The core protocol of the World Wide Web.
(ii) HTTPS: A protocol used between a web client and a web server permits secure data transmissions.
(iii) FTP: Used between computers for sending and receiving data. Enables a client to send and receive complete files from a server.

Main components of RFID system
1. RFID tag: It has silicon microchip attached to a small antenna and mounted on a substrate.
2. A reader: It has a scanner with antennas to transmit and receive signals, used for communication.
3. A controller: It is the host computer with a microprocessor which receives the reader input and process the data.

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.

INTERNET:
(i) The Internet is a worldwide system of computer networks- A network of networks where the users at any one computer can get information from any other computer.
(ii) The Internet is a network of global connections - comprising private, public, business, academic and government networks connected by guided, wireless and fiber-optic technologies.
(iii) The unique aim was to generate a network that would permit users of a research computer from one university to "talk to" research computers on other universities.
(iv) The Internet denotes to the global communication system, including infrastructure and hardware, whereas the web is one of the services interconnected over the Internet.
INTRANET:
(i) Intranet is a private network within an enterprise to share company data and computing resources between the employees.
(ii) It may consist of many interlinked local area networks.
(iii) It includes connections through one or more gateway (connects two networks using different protocols together known as protocol convertor) computers to outside Internet.
EXTRANET: Extranet is a private network that uses Internet technology and the public telecommunication system to securely share business information with suppliers, vendors, partners, customers, or other business.