The key difference is that: 1  With an emulator, you want the output exactly match what the object you are emulating would produce. 2  With a simulator, you want certain properties of your output to be similar to what the object would produce.
https://stackoverflow.com/questions/1584617/simulator-or-emulator-what-is-the-difference
Emulation is the process of mimicking the outwardly observable behavior to match an existing target. The internal state of the emulation mechanism does not have to accurately reflect the internal state of the target which it is emulating.
https://stackoverflow.com/questions/1584617/simulator-or-emulator-what-is-the-difference
In computer science both a simulation and emulation produce the same outputs, from the same inputs, that the original system does; However, an emulation also uses the same processes to achieve it and is made out of the same materials.
https://stackoverflow.com/questions/1584617/simulator-or-emulator-what-is-the-difference
Fortunately, there’s a new generation of network portals on the rise, like Emulation Cloud, intended to support these new requirements by leveraging the high degrees of programmability and open Application Programming Interfaces (APIs) in next-generation optical platforms.
http://www.ciena.com/insights/what-is/What-is-Emulation-Cloud.html
The emulator executes the application by translating the byte-code into a form that can be executed by the host computer running the emulator. To understand the subtle difference between simulation and emulation, imagine you are trying to convince a child that playing with knives is dangerous.
https://stackoverflow.com/questions/1584617/simulator-or-emulator-what-is-the-difference
And remember products that allowed you to have ICE (In Circuit Emulation) capabilities to debug a PC platform, I find the use of the term Emulation to be a somewhat of a misnomer for software that SIMULATES the behaviour of a piece of hardware.
https://stackoverflow.com/questions/1584617/simulator-or-emulator-what-is-the-difference
Emulation is the use of a specialist computer (popularly called “Emulator“) which automatically maps the RTL representation of a Design to its internal programmable gate-array to perform the Functional Verification of the Hardware and Software of the Design.
http://www.learnuvmverification.com/index.php/2016/10/31/what-is-emulation/
MAME is an arcade game emulator; Hyperterm is a (not very good) terminal emulator. There's no need to model the arcade machine or a terminal in detail to get the desired emulated behavior. Flight Simulator is a simulator; SPICE is an electronics simulator.
https://stackoverflow.com/questions/1584617/simulator-or-emulator-what-is-the-difference
Emulator, on the other hand, actually does what the thing being emulated does, and in doing so it too appears to be doing the same thing. An emulator may use different set of protocols for mimicking the thing being emulated, but the result/outcome is always the same as the original object.
https://stackoverflow.com/questions/1584617/simulator-or-emulator-what-is-the-difference
EDIT: Other responses have pointed out that the goal of an emulation is to able to substitute for the object it is emulating. That's an important point. A simulation's focus is more on the modelling of the internal state of the target -- and the simulation does not necessarily lead to emulation.
https://stackoverflow.com/questions/1584617/simulator-or-emulator-what-is-the-difference
what is emulation
Emulation is the process of mimicking the outwardly observable behavior to match an existing target.