Can you explain the main principles of garbage collection in managed programming languages?

Garbage Collector (GC) in managed languages like Java automatically frees memory occupied by objects that are no longer used by the program.

Main principles:

• Reachability tracking: GC determines which objects are reachable from root references (stack, static variables, etc.). Unreachable objects are considered garbage.
• Marking and sweeping: First, GC marks all reachable objects, then frees the memory occupied by unmarked (unreachable) objects.
• Different algorithms: There are various approaches — copying, reference counting, generational collection (young/old generation), each optimized for different scenarios.

For example, generational collection is based on the fact that most objects live for a short time, so the young generation is collected more frequently, and the old generation less often, increasing efficiency.