I read the book Software Exorcism which is authored by Bill Blunden, I read there is definition about debugger, author said it's a neutral frame of reference. English is not my native language, is there any one can help me understand it, thanks a lot.
A "frame of reference" is a way of looking at something. In this context, a "neutral frame of reference" is a way of looking at a programming problem where the programmer can make observations about a program without affecting it (i.e. neutral). I think the term "objective frame of reference" would also be appropriate.
WordWeb defines this noun phrase:
Frame of reference (n): 1) A system that uses coordinates to establish position. 2) A system of assumptions and standards that sanctions behavior and gives it meaning.
This clarifies the meaning in a simple way as while debugging, we not only know where the flaw is but also know its position in coding.