Information System Boundary definition in Computer Security terms:
Synonym(s): Authorization Boundary
All components of an information system to be authorized for operation by an authorizing official and excludes separately authorized systems, to which the information system is connected.
Source(s): CNSSI 4009-2015 NIST SP 800-137 NIST SP 800-161 NIST SP 800-37 Rev. 1 NIST SP 800-39 NIST SP 800-53 Rev. 4 NIST SP 800-30 NIST SP 800-53A Rev. 4
reference: CSRC Glossary