Simulation vs Emulation

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Simulation is the imitation of some real thing, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system.
Simulation is used in many contexts, such as simulation of technology for performance optimization, safety engineering, testing, training, education, and video games. Training simulators include flight simulators for training aircraft pilots in order to provide them with a lifelike experience.

The simulator simulates the behavior of your system through software, so you can simulate a program that will run on a microcontroller or on a FPGA. And you can simulate the behavior of a hardware system using mathematical equations.


In computing, an emulator is hardware and/or software that duplicates (or emulates) the functions of a first computer system in a different second computer system, so that the behavior of the second system closely resembles the behavior of the first system. This focus on exact reproduction of external behavior is in contrast to some other forms of computer simulation, in which an abstract model of a system is being simulated. For example, a computer simulation of a hurricane or a chemical reaction is not emulation.
The emulator normally uses hardware to emulate the behavior of your system. For example, if you want to know the way your program will run on a specific microcontroller (which will be a part of a car afterwards) you get an emulator for that microcontroller and connect the microcontroller to it (you may need to connect the emulator to the PC) and see the real output. With an emulator you can see the behavior in different stats of operations, like different temperatures or when it is connected to other peripherals.
More
http://en.wikipedia.org/wiki/Emulator
http://en.wikipedia.org/wiki/Simulation

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