Explain the Go memory model and garbage collection.

Go Memory Model and GC: • Concurrent, tri-color mark-and-sweep GC • Low-latency, sub-millisecond pauses • Automatic memory management • Stack vs heap allocation • Escape analysis determines allocation • GOGC environment variable controls GC Memory Model: • Happens-before relationships • Channel operations provide synchronization • Mutex and atomic operations • Memory reordering considerations GC Tuning: • GOGC=100 (default) • runtime.GC() force collection • runtime.ReadMemStats() for monitoring