A simulation is a computer model that mimics the operation of a real or proposed system and it is time based and takes into account all the resources and constraints involved.
Cost
Repeatability
Time
A mobile simulator also known as emulator, a software that can be installed on a normal desktop which creates a virtual machine version of a mobile device such as a mobile phone, iPhone, other smartphone within the system. Mobile simulator allows the user to execute the application under test on their computer as if it was the actual mobile device.