Thread count refers to the number of threads woven per square inch of fabric. It's not just a number — it's a texture. Lower counts (like 400–600TC) tend to feel light, crisp, and breathable, great for warm sleepers. Higher counts (800–1200TC) feel denser, smoother, and more substantial, closer to a hotel-luxury feel. There's no universal "best" — just the feel that matches how you like to sleep.