Cybersecurity glossary
What is firewall?
Definition
A firewall controls network traffic between zones, such as the internet and an internal network, allowing or blocking connections according to rules.
Why it matters
Home routers and operating systems include basic firewalls; businesses also use next-generation firewalls and web application firewalls (WAFs) that inspect application traffic. A firewall cannot stop attacks that arrive through allowed channels such as email or a user’s browser.
Common questions about firewall
See also
Sources
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