1. An information system comprising a collection of interconnected computers or devices.

Source: Cyber Threats to Elections – A Lexicon, Cyber Threat Intelligence Integration Center & Office of the Director of National Intelligence,

2. An Information system implemented with a collection of interconnected components, which may include routers, hubs, cabling, telecommunications controllers, key distribution centers, and technical control devices. (NIST Glossary of Information Security Terms – NIST IR 7298 – Revision 2).

Source: NSTAC Report to the President on a Cybersecurity Moonshot, National Security Telecommunications Advisory Committee (NSTAC),