The simulation of the software and/or hardware upon which other software runs.
Sources:
NIST SP 800-125
NIST SP 800-190
from
NIST SP 800-125
A methodology for emulation or abstraction of hardware resources that enables complete execution stacks including software applications to run on it.
Sources:
NIST SP 800-125A
The use of an abstraction layer to simulate computing hardware so that multiple operating systems can run on a single computer.
Sources:
NIST SP 800-44 Version 2
The simulation of the software and/or hardware upon which other software runs; this simulated environment is called a virtual machine
Sources:
NISTIR 8006
from
NIST SP 800-125 - Adapted