Program memory is partitioned into text, global, stack, and heap segments, of which only the heap can grow and shrink under program control at runtime while the others are fixed at compile time. Each function call — including each recursive call, since a function calling itself is no different from one function calling another — receives a stack frame holding its local variables and execution state, and that frame is reclaimed when the call returns; nodes of a dynamically built tree, by contrast, are allocated in the heap and persist until explicitly deallocated. The concept belongs to memory management in systems programming and explains how a logically non-linear structure such as a binary search tree is realised over linear memory through pointer links, and how recursive construction of that structure interleaves transient stack growth with persistent heap allocation.
Program memory is partitioned into text, global, stack, and heap segments, of which only the heap can grow and shrink under program control at runtime while the others are fixed at compile time. Each…