Firewall (noun)

1. A security system for controlling access to or from a private network.
2. A barrier to prevent the spread of fire.

Origin:

Compound word, from 'fire' + 'wall'.

Examples:

1. The company implemented a firewall to protect its sensitive data.
2. The firewall blocked unauthorized access to the company's network.
3. The firewall is designed to prevent malicious traffic from entering the network.
4. The firewall is updated regularly to stay ahead of new security threats.
5. The firewall provides an extra layer of protection for the company's valuable information.