Understanding Garbage Collection (GC) in .NET — How It Works and When It Matters

Garbage Collection (GC) in .NET Memory management is one of the most important concepts in .NET. Developers often say “the Garbage Collector handles memory for you,” but few can clearly explain how it works, why it exists, and what you can do to work with it instead of against it . This guide breaks down .NET’s Garbage Collection (GC) in a simple, practical way — with definitions, diagrams, examples, and real-world scenarios. What Is Garbage Collection? Garbage Collection (GC) is an automatic memory management system in .NET. Its job is to: Allocate memory for new objects Track which objects are still in use Free memory for objects that are no longer needed Prevent memory leaks Reduce developer errors like dangling pointers In short: GC keeps your application healthy by cleaning up unused objects automatically. How GC Works in .NET The .NET GC uses a generational, mark‑and‑compact algorithm. Let’s break that down. 1. Generations (Gen 0, Gen 1, Gen 2) Objects are grouped into generation