_____X__________ is a network security system that acts as a barrier between a trusted internal network and untrusted external networks, such as the Internet, in order to prevent unauthorized access and protect against malicious attacks. Identify X from the following options:

Correct option is A

A firewall is a network security system that acts as a protective barrier between a trusted internal network and untrusted external networks such as the Internet. It monitors incoming and outgoing network traffic and applies predefined security rules to allow or block data packets. By filtering traffic, a firewall helps prevent unauthorized access, cyberattacks, and malicious activities, making it a fundamental component of network security.
Important Key Points:
1. What is a Firewall? A firewall is a security system (hardware, software, or both) that controls network traffic based on security rules.
2. Primary Function: Protects internal networks from unauthorized access and external threats.
3. How It Works? Inspects data packets and decides whether to allow or block them according to defined policies.
4. Types of Firewalls:
· Packet-filtering firewall
· Stateful inspection firewall
· Proxy firewall
· Next-generation firewall (NGFW)
5. Where Firewalls Are Used? Home networks, corporate networks, data centers, and cloud environments.
6. Security Role: Acts as the first line of defense in network security.
Knowledge Booster:
· Why option (b) Virus is incorrect? A virus is malicious software, not a protective security system.
· Why option (c) Malware is incorrect? Malware refers to harmful programs, not defensive mechanisms.
· Why option (d) Modem is incorrect? A modem is a communication device used to connect to the internet, not to secure the network.