What Does Call Stack Mean?
A call stack, in C#, is the list of names of methods called at run time from the beginning of a program until the execution of the current statement.
Techopedia Explains Call Stack
Call stack is organized as “stack,” a data structure in memory for storing items in a last-in-first-out manner, so that the caller of the subroutine pushes the return address onto the stack and the called subroutine, after finishing, pops the return address off the call stack to transfer control to that address.