---
title: "What is network security"
subject: "Computer Networks and Security"
chapter: 8
key: "semester_7/computer_networks_and_security:network-security-meaning"
source: https://www.bctengineer.com/q/semester_7/computer_networks_and_security/network-security-meaning
site: BCT Engineering
---

# What is network security

Computer Networks and Security · Chapter 8: Network Security

- Asked in: 2071 Chaitra, 2 marks; 2070 Chaitra, 3 marks (asked 2 times)
- Video: [Basics Of Network Security ll Information and Cyber Security Course Explained in Hindi](https://www.youtube.com/watch?v=BdDd_Ez4iZs) — 5 Minutes Engineering
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/computer_networks_and_security/network-security-meaning
- Whole chapter: https://www.bctengineer.com/md/semester_7/computer_networks_and_security/chapter-8

## Question

What do you mean by network security?

## Short answer

Network security defends network infrastructure and data against unauthorized access, misuse, and attacks. It ensures confidentiality, integrity, availability (CIA) through firewalls, encryption, authentication, and intrusion detection, and addresses threats like eavesdropping and denial of service.

## Answer

**Network security** is the set of policies, practices and technologies used to protect a computer network and the data travelling on it from unauthorised access, misuse, modification, disruption or destruction. It protects the **confidentiality, integrity and availability (CIA)** of information and network resources.

It covers:
- **Prevention:** firewalls, encryption, authentication, access control, antivirus.
- **Detection:** intrusion detection systems, log monitoring.
- **Response and recovery:** incident handling, backup.

Threats include eavesdropping (sniffing), masquerading, replay, modification of messages, denial of service, viruses, worms and phishing.

Example: a bank encrypts online transactions with SSL/TLS, protects its LAN with a firewall and allows only authorised users to log in.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Network security protects which three properties?
   A. Authentication, billing, logging
   B. Cost, speed, bandwidth
   C. Encryption, routing, addressing
   D. Confidentiality, integrity, availability
   Answer: D. Network security protects the CIA of information and resources. (Key point: CIA)

2. Which is a detection measure?
   A. Backup
   B. Firewalls
   C. Intrusion detection systems and log monitoring
   D. Encryption
   Answer: C. Detection includes IDS and log monitoring; firewalls and encryption are prevention. (Key point: Detection measures)

3. Which is a threat listed for networks?
   A. Multiplexing
   B. Subnetting
   C. Routing
   D. Replay and eavesdropping
   Answer: D. Eavesdropping, masquerading, replay, modification, DoS, viruses and phishing are threats. (Key point: Threat example)

## Related in Computer Networks and Security

- [Network security and firewalls](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Anetwork-security-firewall-protect) — Computer Networks and Security, chapter 8
- [Meaning of network architecture](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Anetwork-architecture-meaning) — Computer Networks and Security, chapter 1
- [Network design for 3-star hotel](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Ahotel-network-design) — Computer Networks and Security, chapter 1
- [What is a computer network](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Acomputer-network-definition) — Computer Networks and Security, chapter 1
- [X.25 network and features](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Ax25-network) — Computer Networks and Security, chapter 2
- [Functions of network layer](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Anetwork-layer-functions) — Computer Networks and Security, chapter 4

## Related in other subjects

- [Email security with diagram and protocols](https://www.bctengineer.com/question.md?key=semester_8%2Finternet_and_intranet%3Aemail-security-diagram) — Internet and Intranet, chapter 3
- [Attack types; security of all components](https://www.bctengineer.com/question.md?key=semester_6%2Foperating_system%3Aattack-types-security-protection-components) — Operating System, chapter 8
- [IS security threats and safeguards](https://www.bctengineer.com/question.md?key=semester_8%2Finformation_system%3Ais-security-threats-controls) — Information System, chapter 2
- [Layered approach to security](https://www.bctengineer.com/question.md?key=semester_8%2Finformation_system%3Alayered-security-throughput) — Information System, chapter 2