firewall

word

Definition

A firewall is a security system, often in computers or networks, that controls what information can go in or out to protect against threats. Originally, the word came from a wall designed to stop the spread of fire.

Usage & Nuances

Used mainly in technology and IT contexts. Can refer to both physical hardware devices and software solutions protecting computers/networks. In conversation, 'firewall' almost always means a digital security measure. 'Install a firewall' or 'disable the firewall' are typical phrases. Rarely used in the original sense of a wall stopping fire.

Example Sentences

Every company should have a firewall to protect its data.

basic

My computer's firewall blocked a virus last night.

basic

You should update your firewall regularly.

basic

Sorry, I can't access that site—my firewall keeps blocking it.

natural

Remember to enable your firewall before connecting to public Wi-Fi.

natural

We had to adjust the firewall settings to allow video calls at work.

natural