Garbage collection (GC) is the automatic memory management system in languages like C#, Java, and Lua that periodically identifies and frees memory that is no longer referenced. In business software, GC pauses are invisible. In games running at 60fps, a 16ms GC pause means a dropped frame -- and players notice. Unity developers are intimately familiar with this problem because C# uses a generational garbage collector that can pause the main thread when it runs. The mitigation strategies are well-established: object pooling to avoid allocations, pre-allocating collections to their maximum expected size, using structs instead of classes where possible, caching references instead of creating temporary objects, and minimizing string operations. Incremental garbage collectors spread the work across multiple frames but add complexity. This is one reason AAA engines often use C++ -- manual memory management means zero GC surprises.