# pfSense and Networking Glossary of Terms

> Glossary of pfSense and networking terms - definitions for ACL, CARP, IPsec, NAT, VLAN, QoS, and other concepts explained in the context of pfSense

Source: https://opennix.org/en/docs/pfsense/glossary/


This glossary defines the key terms used throughout pfSense documentation and in networking in general. Each entry includes the acronym expansion (where applicable) and a brief explanation within the context of pfSense. The glossary serves as a reference companion when studying documentation on the [firewall](/docs/pfsense/firewall/pfsense-firewall-rules/), [VPN](/docs/pfsense/vpn/), [VLANs](/docs/pfsense/vlans/pfsense-vlan-setup/), and other sections.

## In This Section

- [Terms and Definitions](/docs/pfsense/glossary/pfsense-terms/) - alphabetical glossary of pfSense and networking terms