https://en.wikipedia.org/wiki/Call_stack
When you call a function, your program jumps to another place in the code. When a function completes, it needs to "return" to the place in the program where it was called from. To get back to the place in the code that called the function, it needs to store that information somewhere. You can think of that as a "stack" of function return addresses. Each time a function calls another one, another entry is put on the call stack.
When you're debugging a program, Visual Studio should have a tab somewhere that shows what functions are on that callstack. If I have a a program that calls a function called Foo, which calls a function called Frobnicate, which calls a function called YourMom, then if you put a breakpoint in YourMom, Visual Studio should show you something like this when the breakpoint is hit:
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YourMom
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Frobnicate
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Foo
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main
Note that the most recently called function is on the top, while the functions that called it are beneath it.
The idea of a call stack is really fundamental, so make sure you get this idea good and internalized. So fundamental, in fact, that if you didn't know what it was before, then I suggest this thread should have been put in the For Beginners section.
If you're having trouble with the actual tools, then I suggest heading to the GDNet Discord chat or some Visual Studio-specific resource.