Explain the working principle of the garbage collector in an automatic memory management system.

Garbage Collector (GC) in an automatic memory management system is responsible for freeing memory occupied by objects that are no longer used by the program.

Working principle:

1. Object tracking: GC determines which objects are reachable (used) from root references (e.g., local variables, stack).
2. Determining unreachable objects: Objects with no references are considered garbage.
3. Memory freeing: GC frees the memory occupied by such objects so it can be reused.

In Go, the garbage collector runs concurrently with the program execution, minimizing pauses. It uses algorithms based on reachability counting and object marking.

Example: if an object is created in a program but references to it are lost, GC will automatically free the memory without the need for explicit deletion.