Model, Software and Processor in the loop

Hello everyone I want to ask you about the Model, Software and Processor in the loop, i want to know if the word "loop" means that our system must be in the loop ?

[Stephen23]

Please do not post duplicate questions:

http://www.mathworks.com/matlabcentral/answers/260223-model-software-and-processor-in-the-loop

http://www.mathworks.com/matlabcentral/answers/260222-model-software-and-processor-in-the-loop