A table of instructions used by a controlled interface to determine what data is allowable and how the data is handled between interconnected systems.
Sources:
CNSSI 4009-2015
A collection of rules or signatures that network traffic or system activity is compared against to determine an action to take—such as forwarding or rejecting a packet, creating an alert, or allowing a system event.
Sources:
NIST SP 800-115
under Ruleset
A set of directives that govern the access control functionality of a firewall. The firewall uses these directives to determine how packets should be routed between its interfaces.
Sources:
NIST SP 800-41 Rev. 1
under Ruleset