The correct answer is  hub.

Key Points

• An Ernet hub, active hub, network hub, repeater hub, multiport repeater, or simply hub is a network hardware device for connecting multiple Ernet devices toger and making m act as a single network segment.
• It has multiple input/output (I/O) ports, in which a signal introduced at input of any port appears at output of every port except original incoming.

Additional Information

• Tim Berners-Lee, a British scientist, invented World Wide Web (WWW) in 1989 while working at CERN.
• The first web page address was http://info.cern.ch/hypertext/WWW/TheProject.html.
• ARPANET adopted TCP/IP on January 1, 1983.
• NCSA Mosaic ran on Windows computers was first browser to surf internet.

The correct answer is 110.

Key Points

• The full form of POP3 is Post Office Protocol version 3.
• It is referred to as a simple mail protocol. The main job of POP3 is to retrieve or copy mail from a remote server and n send that email to specific local client. 
• POP3 is not programmed for handling and synchronising mail in user's mailbox throughout multiple devices. 
• There are two ports used for POP3. These are given below:
  • Port 110- By default POP3 uses Port 110 for retrieving mail.
  • Port 995- POP3 port 995 is used in SSL/TLS.

 Thus  correct answer is 110.

The correct answer is Router.

Key Points

• A router is a networking device that forwards data packets between computer networks.
• Routers perform traffic directing functions on Internet. Data sent through internet, such as a web page or email, is in form of data packets.
• A packet is typically forwarded from one router to anor router through networks that constitute an internet work until it reaches its destination node.
• A router is connected to two or more data lines from different IP networks.
• When a data packet comes in on one of lines, router reads network address information in packet header to determine ultimate destination.
• Then, using information in its routing table or routing policy, it directs packet to next network on its journey.
• The most familiar type of IP routers are home and small office routers that simply forward IP packets between home computers and Internet.
• More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to powerful core routers that forward data at high speed along optical fiber lines of Internet backbone.

• Hacking is an act committed by an intruder by accessing your computer system without your permission
• A Denial-of-Service (DoS) attack is an explicit attempt by attackers to deny service to intended users of that service
• Phishing is fraudulent attempt to obtain sensitive information such as usernames, passwords, and credit card details by disguising as a trustworthy entity in an electronic communication
• In spamming, unsolicited bulk messages are sent to a large number of users, indiscriminately

The correct answer is 1000.100.10.1.

Key Points

• A network interface on a system is uniquely identified by its 32-bit IPv4 address.
• The format of an IPv4 address is typically four 8-bit fields separated by periods, printed in decimal digits.
• A byte of IPv4 address is represented by each 8-bit field.
• Dotted-decimal format is a common name for this way of expressing bytes of an IPv4 address.
• The network component and host part are additional divisions made in IPv4 address's bytes.
• Each octet in IPv4 address can have a value from 0 to 255, but in option 4 first octet value is 1000 which is not valid. Consequently, it can not be a valid IPv4 address.

Important Points

• The unique number allocated to network is specified in network component.
• The allocated class of network is also identified by network component.
• The portion of IPv4 address that you give to each host is known as host part.
• This machine on your network is identified by host part specifically. 

The Correct Answer is Metropolitan Area Network.

• A metropolitan area network (MAN) is a computer network that interconnects users with computer resources in a geographic region of size of a metropolitan area.

Additional Information

A computer network is a group of computers linked to each or that enables computer to communicate with anor computer and share its resources, data, and applications.

On basis of size of network it is mainly of four types:

Computer Network Types

• LAN(Local Area Network): Local Area Network is a group of computers connected to each or in a small area such as a building, or office.
• PAN(Personal Area Network): It is a network arranged within an individual person, typically within a range of 10 meters.
• MAN(Metropolitan Area Network): A metropolitan area network is a network that covers a larger geographic area by interconnecting a different LAN to form a larger network.
• WAN(Wide Area Network): A Wide Area Network is a network that extends over a large geographical area such as states or countries.

The correct answer is option (3)

Wide area network (WAN)

Concept:-

A wide-area network (WAN) is essentially a collection of interconnected local-area networks (LANs) or or networks.

Key Points

• The Internet is biggest WAN in world, and a WAN is essentially a network of networks.
• WANs are inherently expandable and have a big capacity, connecting many computers over a wide area.
• They make it easier to share local resources. To connect LANs and MANs to Internet, WAN offers uplinks.

Additional Information LAN:- A local area network, or LAN for short, is a type of network that connects a few buildings toger or individual residences or offices.

MAN:- A metropolitan area network (MAN) is a type of computer network that links computers in an area with many buildings, such as a single large metropolis, several smaller cities, or any or sizeable area.

VPN:- The term "Virtual Private Network," or VPN, refers to possibility of creating a secure network connection when utilizing public networks.

The correct answer is Dynamic Host Configuration Protocol.

Key Points

• DHCP is acronym of Dynamic Host Configuration Protocol.
• A Dynamic Host Configuration Protocol is a network server that automatically provides and assigns IP addresses, default gateways and or network parameters to client devices.
• It will help to prevent duplication of addresses and also help administrator keep good records.
• DHCP is designed to improve efficiency of allocating IP addresses.
• DHCP services exist for networks running both Internet Protocol version 4 (IPv4) and  Internet Protocol version 6 (IPv6).
• The IPv6 version of DHCP protocol is commonly called DHCPv6.

Additional Information

• Or common network protocols examples:
  • Address Resolution Protocol (ARP)
  • File Transfer Protocol(FTP)
  • HyperText Transfer Protocol(HTTP)
  • Post Office Protocol (POP3)
  • Simple Mail Transfer Protocol (SMTP)
  • Secure Shell Protocol (SSH)

The correct answer is Used to deliver data on World Wide Web.

Key Points

• The HTTP protocol is used to deliver data on World Wide Web 
  • It stands for Hypertext Transfer Protocol.
  • It is an application layer protocol designed within framework of Internet Protocol Suite.
  • It is base of data communication on World Wide Web.
  • It provides a standard for web browsers that facilitates users to exchange information over internet. 
  • A typical flow over HTTP involves a client machine requesting a server, which n sends a response message.
  • An HTTP request is a way internet communications platforms such as web browsers ask for information y need to load a website.
  • Each HTTP request made across Internet carries with it a series of encoded data that carries different types of information.

Additional Information

• Hypertext Transfer Protocol Secure (HTTPS)
  • It is protocol where encrypted HTTP data is transferred over a secure connection.
  • It ensures data security over network - mainly public networks like Wi-Fi. 
  • HTTPS encryption is done bi-directionally, which means that data is encrypted at both client and server sides.

The Correct Answer is "Web administration".

Important Points

• An Internet service provider (ISP), is a company that provides Internet connections and services to individuals and organizations.
• In addition to providing access to Internet, ISPs may also provide software packages and a personal Web site or home page.
• ISPs can host Web sites for businesses and can also build Web sites mselves.
• ISPs are all connected to each or through network access points and public network facilities on Internet backbone.

Some of se services include:

• Email services
• Web hosting services
• Domain Registration
• Browser and software package.                                            

Key Points

• An internet service provider (ISP) is a company that provides web access to both businesses and consumers.
• ISPs may also provide or services such as email services, domain registration, web hosting, and browser services.
• An ISP is considered to be an information service provider, storage service provider, internet network service provider (INSP), or a mix of all of m.
• Internet use has evolved from only those with university or government accounts having access to nearly everyone having access, wher it's paid or free.
• Access has gone from dial-up connections to high-speed broadband technology.