Topic summary
Web security

Extracted from the Wikipedia article Internet security.
Web security
Firewalls restrict incoming and outgoing network packets. Only authorized traffic is allowed to pass through it. Firewalls create checkpoints between networks and computers. Firewalls can block traffic based on IP source and TCP port number. They can also serve as the platform for IPsec. Using tunnel mode, firewalls can implement VPNs. Firewalls can also limit network exposure by hiding the internal network from the public Internet.