A Firewall is a security system that monitors and controls network traffic. It acts as a barrier between trusted internal networks and untrusted external networks.
Key Functions of Firewalls:
1. Filter incoming and outgoing traffic
2. Block unauthorised access attempts
3. Prevent malware spread
4. Log network activity
5. Implement security policies
Types of Firewalls:
1. Packet filtering firewalls
2. Stateful inspection firewalls
3. Application layer firewalls
4. Next-generation firewalls Firewalls can be hardware devices, software programs, or a combination of both. They are essential for network security in both personal and business environments.