Simulator vs simulation explained: learn why one is the tool and the other the process, with clear flight and train examples and key edge cases.
A simulator is the tool or system used to reproduce real-world behaviour; a simulation is the modelled process, scenario or run that the tool creates. Across general flight, train and other simulation, the simulator is what you operate, while the simulation is what happens—though software naming often blurs the distinction.
Simulator vs simulation at a glance
A simulator is a mechanism, whereas a simulation is the activity or result produced with it.
| Term | Meaning | Flight-sim example |
|---|---|---|
| Simulator | Software, hardware or an integrated system designed to imitate something | Microsoft Flight Simulator, X-Plane or a full cockpit training device |
| Simulation | The reproduced operation, scenario or individual run | A virtual flight from Manchester to Dublin with live weather and an engine failure |
If you finish that flight and return to the menu, the simulator still exists, but that particular simulation has ended. Likewise, a train simulator is the software and control environment; a timetable service with signals, traffic and adhesion conditions is a simulation running inside it.
A simulator may combine code, displays, physical controls, sound and motion equipment. Our explanation of how a flight simulator converts control inputs into aircraft behaviour shows how those parts work together.
How do the model, simulation and simulator fit together?
The model contains the rules, the simulation runs those rules, and the simulator packages the result into a usable system.
- Model: The equations, data and logic representing aerodynamics, engines, weather, signalling or another real system.
- Simulation: The execution of that model under chosen starting conditions and inputs.
- Simulator: The software or equipment that runs the model and presents its state to a user or connected system.
In a flight simulator, the aerodynamic model calculates forces from airspeed, angle of attack and control position. Running those calculations as the aircraft moves creates the simulation; the application, visuals, controls and supporting systems form the simulator. See our technical overview of how flight physics are calculated in real time for the model layer in more detail.
The boundaries are not absolute. A software package can be called both simulation software and a simulator because it contains the model, executes it and provides the interface.
Can a simulation exist without a simulator?
A simulation can exist without a dedicated, interactive simulator.
An engineer might run a batch calculation, spreadsheet model or automated test that simulates thousands of cases without a cockpit, cab or user-controlled environment. That process is still a simulation, although its software may be described as a modelling tool rather than a simulator.
The reverse is also possible: an installed simulator can sit idle without running an active simulation. A recorded replay is another edge case—it may display the results of an earlier simulation rather than calculate a new one.
Why are simulator and simulation used interchangeably?
The terms overlap because everyday and commercial usage is less strict than technical usage.
“Flight simulation” can mean the entire hobby or technical discipline, while “flight simulator” usually means a particular program or training device. The abbreviation “sim” is even looser: depending on context, it can mean the software, the session or the genre.
A product containing “Simulator” in its name is not automatically realistic or professionally certified. The name describes its purpose, not the accuracy of its flight model, systems, controls or operating procedures.
Which term should you use?
Use the word that identifies whether you mean the tool, the activity or the individual scenario.
- Say simulator for the software or equipment: “I installed a new flight simulator.”
- Say simulation for a run or reproduced event: “The simulation included a hydraulic failure.”
- Say flight simulation or train simulation for the wider hobby and field.
- Keep the official wording when naming a product, even if casual usage would choose the other term.
Is a simulator the same as an emulator?
No: a simulator reproduces behaviour, while an emulator tries to reproduce another system closely enough that software or devices designed for the original can operate as though it were present.
The distinction depends on what must be compatible, so some products combine both techniques. Our comparison of simulation and emulation in practical use explains where that boundary lies.