Sleep isn't just an on-or-off switch. When you fall asleep, your brain follows a predictable pattern, cycling through different stages throughout the night. Think of it like a roller coaster ride that repeats every 90 minutes or so.

These stages are grouped into two main types: Non-Rapid Eye Movement (N-REM) sleep and Rapid Eye Movement (REM) sleep.

N-REM sleep itself has three distinct stages:

• N1 (Light Sleep): This is the drowsy, transitional phase right after you close your eyes. Your heartbeat and breathing slow down, and your muscles relax. You can be easily woken up during this stage. It's the