Can you explain how garbage collection works in programming languages?

Garbage Collector (GC) is a memory management mechanism that automatically frees memory occupied by objects that are no longer used by the program.

Working principle:

• The collector tracks objects in memory and determines which ones are reachable (used) from root references (e.g., local variables, static fields).
• Objects that are not reachable from root references are considered unreachable and are subject to removal.
• GC frees the memory of these objects, preventing memory leaks.

In C#, the garbage collector works on a generational model:

• Objects are divided into generations (0, 1, 2) based on their lifetime.
• Young objects (generation 0) are checked more frequently, as most objects quickly become unnecessary.
• Objects that survive several collections are promoted to older generations.

This increases the efficiency of GC and reduces overhead on memory management.