Computer Networks: An Overview

 

What is a Computer Network?

A computer network is a collection of computers, servers, mainframes, network devices, and other devices connected to share data and resources. These devices can communicate with each other over a variety of transmission media like cables, wireless connections, or satellite links. A network enables resource sharing such as files, printers, and internet access between connected devices.

How Do Computer Networks Work?

Networks work by using protocols to govern the communication between devices. These protocols include TCP/IP, HTTP, FTP, and many others. These protocols define the rules for data transfer, error checking, and communication between devices. A network can be connected via wired (e.g., Ethernet) or wireless (e.g., Wi-Fi, Bluetooth) connections. Routers and switches play key roles in routing data efficiently across the network.

Advantages of Computer Networks:

1. Resource Sharing: Users can share resources like printers, files, and internet connections, reducing costs.
2. Centralized Data Management: Data can be stored and managed on a central server, ensuring consistency and easier backup.
3. Improved Communication: Email, instant messaging, and video conferencing allow quick communication between users.
4. Scalability: Networks can be easily expanded to add more users or devices.
5. Remote Access: Users can access resources and data remotely, providing flexibility for remote working or accessing information from anywhere.

Disadvantages of Computer Networks:

1. Security Concerns: As multiple devices are connected, the network becomes more vulnerable to cyber-attacks and data breaches.
2. Complexity: Setting up and managing large networks can be complex and require skilled professionals.
3. Cost: Initial setup costs, maintenance, and the need for network hardware can be expensive.
4. Data Loss or Corruption: If not properly maintained, network data can be lost or corrupted, especially if there is a failure in the system.
5. Network Congestion: Overloading the network with too much data or too many devices can slow down the performance.

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25 MCQs on Computer Networks

1. What is a computer network? A) A single computer
   B) A group of connected devices
   C) A type of virus
   D) A database
   Answer: B) A group of connected devices

2. Which device is used to connect two or more computers to share resources? A) Switch
   B) Router
   C) Hub
   D) All of the above
   Answer: D) All of the above

3. Which of the following is the most common type of network? A) LAN
   B) WAN
   C) MAN
   D) PAN
   Answer: A) LAN (Local Area Network)

4. What does IP stand for in computer networking? A) Internet Provider
   B) Internal Protocol
   C) Internet Protocol
   D) Integrated Protocol
   Answer: C) Internet Protocol

5. What is the role of a router in a network? A) To connect devices within the same network
   B) To manage traffic between networks
   C) To store files
   D) To detect errors in data transmission
   Answer: B) To manage traffic between networks

6. Which of the following is an example of a wireless network? A) Bluetooth
   B) Ethernet
   C) Fibre optics
   D) Coaxial cable
   Answer: A) Bluetooth

7. What does LAN stand for? A) Local Area Network
   B) Long Area Network
   C) Large Area Network
   D) Local Active Network
   Answer: A) Local Area Network

8. Which of these is a disadvantage of a computer network? A) Security risks
   B) File sharing
   C) Improved communication
   D) Flexibility
   Answer: A) Security risks

9. Which network device amplifies and forwards data between devices in a network? A) Router
   B) Hub
   C) Modem
   D) Repeater
   Answer: D) Repeater

10. Which protocol is used for transferring files over the internet? A) HTTP
    B) FTP
    C) SMTP
    D) IMAP
    Answer: B) FTP (File Transfer Protocol)

11. Which of the following is NOT a type of computer network? A) PAN
    B) LAN
    C) WAN
    D) B2B
    Answer: D) B2B (Business to Business)

12. What does the term 'IP address' refer to? A) A unique identifier for a computer in a network
    B) A protocol used for email communication
    C) A type of network cable
    D) A computer virus
    Answer: A) A unique identifier for a computer in a network

13. What is the maximum range of a typical Wi-Fi network? A) 10 meters
    B) 50 meters
    C) 100 meters
    D) 200 meters
    Answer: B) 50 meters

14. What does the 'HTTP' protocol stand for? A) HyperText Transmission Protocol
    B) HyperText Transport Protocol
    C) HyperText Transfer Protocol
    D) HyperText Transmit Protocol
    Answer: C) HyperText Transfer Protocol

15. Which type of network is typically used by large companies to connect their different office branches worldwide? A) LAN
    B) MAN
    C) WAN
    D) PAN
    Answer: C) WAN (Wide Area Network)

16. What is the main function of a switch in a computer network? A) To route data between different networks
    B) To connect devices within the same network
    C) To amplify signal strength
    D) To translate protocols
    Answer: B) To connect devices within the same network

17. What is a common security threat in a computer network? A) Encryption
    B) Phishing
    C) File sharing
    D) Network expansion
    Answer: B) Phishing

18. Which device is used to provide internet access to a local network? A) Hub
    B) Modem
    C) Switch
    D) Router
    Answer: B) Modem

19. Which topology connects all devices in a loop or circular fashion? A) Star topology
    B) Bus topology
    C) Ring topology
    D) Mesh topology
    Answer: C) Ring topology

20. Which of the following is the correct order of layers in the OSI model? A) Physical, Data Link, Network, Transport, Session, Presentation, Application
    B) Application, Transport, Session, Network, Data Link, Physical
    C) Physical, Network, Data Link, Transport, Session, Presentation, Application
    D) Data Link, Network, Application, Transport, Session, Presentation, Physical
    Answer: A) Physical, Data Link, Network, Transport, Session, Presentation, Application

21. What is a VPN used for in computer networking? A) Transferring files securely
    B) Connecting a remote user to a private network
    C) Sending emails
    D) Protecting against malware
    Answer: B) Connecting a remote user to a private network

22. Which of the following is used to secure wireless networks? A) WEP
    B) WPA
    C) WPA2
    D) All of the above
    Answer: D) All of the above

23. Which of the following is a common method to increase the security of a network? A) Using a firewall
    B) Disabling all network devices
    C) Installing software updates
    D) Both A and C
    Answer: D) Both A and C

24. What is the main difference between a hub and a switch? A) A switch can filter traffic, while a hub cannot.
    B) A hub is faster than a switch.
    C) A hub uses wireless communication, while a switch uses wired.
    D) A hub connects to the internet, but a switch does not.
    Answer: A) A switch can filter traffic, while a hub cannot.

25. Which of the following is a characteristic of the "client-server" network model? A) Clients store all data and resources.
    B) Servers provide resources and services to clients.
    C) Clients and servers both share equal responsibilities.
    D) No central control is needed.
    Answer: B) Servers provide resources and services to clients.