How is automatic garbage collection implemented in managed programming languages?

Automatic garbage collection (Garbage Collection, GC) in managed languages like C# is implemented through a special mechanism that tracks objects in memory and frees those that are no longer referenced.

Main principles of GC operation:

• Reference tracking: GC determines which objects are reachable from root references (e.g., local variables, static fields).
• Identifying unreachable objects: Objects with no references are considered garbage.
• Memory freeing: GC releases the memory occupied by unreachable objects.
• Generations: To optimize garbage collection, it is divided into generations (Gen 0, Gen 1, Gen 2), which allows collecting young objects more frequently and long-lived objects less often.

Example in C#:

class Program
{
    static void Main()
    {
        var obj = new object();
        // obj is used
        obj = null; // object becomes unreachable
        GC.Collect(); // forced garbage collection (rarely used in real applications)
    }
}

Thus, the programmer is relieved from manually managing memory, reducing errors related to memory leaks.