PF (Packet Filter)

A Packet Filter (PF) is a security technology that monitors and controls the data traveling in and out of a computer network. Think of it as a security guard that examines each "package" of information—called packets—based on set rules. It decides whether to allow, block, or modify these packets to protect the network from unauthorized access, malicious attacks, or unwanted traffic. PF is commonly used in firewalls to ensure only legitimate data enters or leaves a network, helping to maintain security and integrity without slowing down overall communication.