The simulation of the software and/or hardware upon which other software runs.
NIST SP 800-125
NIST SP 800-190
(NIST SP 800-125)
The use of an abstraction layer to simulate computing hardware so that multiple operating systems can run on a single computer.
NIST SP 800-44 Version 2
A methodology for emulation or abstraction of hardware resources that enables complete execution stacks including software applications to run on it.
NIST SP 800-125A