Simulasi nyaéta tironan tina sababaraha alat atawa tina kaayaan nu sabenerna. Percobaan simulasi dipaké keur ngagambarkeun kaayaan nu penting tina paripolah sistim sacara fisik atawa abstrak ku paripolah sistim séjénna.

Simulasi dipaké dina sababaraha hal, kaasup pa-model-an sistim alami, sarta sistim manusa keur mikanyaho leuwih teleb kana sistim operasina; sarta simulasi dina téhnologi sarta rékayasa kaamanan nu mana hasilna bakal dipaké keur nguji hal-hal nu pakait dina kaayaan nu sabenerna.  Simulasi, maké hiji simulator atawa percobaan séjénna nu dijieun dina kaayaan fiktif ahirna bisa nembongkeun efek nu sabenerna tina sababaraha kaayaan nu mungkin.

Simulasi fisik jeung interaktif 
Simulasi fisik nujul ka simulasi nu ngaganti objék fisik pikeun nu nyaanna. Nu mindeng dipilih salaku objék fisik kalawan alesan leuwih leutik jeung leuwih murah batan objék atawa sistim nu enyaan.

Simulasi interaktif, nu mangrupa simulasi fisik anu husus sarta mindeng disebut salaku simulasi human in the loop, hartina simulasi fisik nu ngaaubkeun manusa, kawas modél dina simulator pesawat hiber.

Computer simulation

Main article: Computer simulation
Related article: Model

Computer simulation, has become a useful part of modeling many natural systems in physics, chemistry and biology, and human systems in economics and social science (the computational sociology) as well as in engineering to gain insight into the operation of those systems.  In such simulations the model behaviour will change according to a set of initial paraméters such as a metéorological modél.
Computer simulations are often considered human out of the loop simulations.

Traditionally, the formal modéling of systems has been via a mathematical model, which attempts to find analytical solutions to problems which enables the prediction of the behaviour of the system from a set of paraméters and initial conditions. Computer simulation is often used an adjunct to, or substitution for, modéling systems for which simple closed form analytic solutions are not possible.  There are many different types of computer simulation, the common féature they all share is the attempt to generate a sample of representative scenarios for a modél in which a complete enumeration of all possible states of the modél would be prohibitive or impossible.

It is incréasingly common to héar simulations of many kinds referred to as "synthetic environments". This label has been adopted to broaden the definition of "simulation" to encompass virtually any computer-based representation.

Simulation in computer science

In computer science, simulation has an even more a specialized méaning: Alan Turing uses the term "simulation" to refer to what happens when a digital computer runs a state transition table (runs a program) that describes the state transitions, inputs and outputs of a subject discrete-state machine.  The computer simulates the subject machine.

In computer programming, a simulator is often used to execute a program that has to run on some inconvenient type of computer.  For example, simulators are usually used to debug a microprogram. Since the operation of the computer is simulated, all of the information about the computer's operation is directly available to the programmer, and the speed and execution of the simulation can be varied at will.

Simulators may also be used to interpret fault trees, or test VLSI logic designs before they are constructed.  Many vidéo games are also simulators, implemented inexpensively.  These are sometimes called "sim games".

In theoretical computer science the term simulation represents a relation between state transition systems. This is useful in the study of operational semantics.

References
 Roger D. Smith: Simulation Article, Encyclopedia of Computer Science, Nature Publishing Group, ISBN 0-333-77879-0.
 Roger D. Smith: "Simulation: The Engine Behind the Virtual World" , eMatter, December, 1999.

See also 
emulator
modeling
simulated reality
 Mastering Simulation: Online Course
 Simulation Interoperability Standards Organization
 United States Defense Modeling and Simulation Office 

Operations research
Rékayasa