* Case when we should use a Simulator: Simulators are typically used in software testing situations where the goal is to ensure that the application functions as intended when interacting with external applications or environments.

For example, you could wish to see if an application can communicate data to another application. Because the actual hardware configuration is unlikely to have much of an impact on data transfers for your program, a simulated environment will usually suffice. Simulated testing environments are also useful for ensuring that an application's interface shows properly across a range of screen resolutions.


* Case when we should use an Emulator: When you need to test how software interacts with underlying hardware or a combination of hardware and software, emulators come in handy.

For example, if we want to discover if a firmware update will cause issues with our software or not, we can find out with the help of an emulator. Alternatively, we could want to know how our program performs when run on multiple CPUs or with varying memory allocations. Emulators come in handy in these situations as well.