Is it OK to turn off BitLocker?

Hey there, I'm curious about something. I've been hearing about BitLocker, and I'm wondering if it's okay to turn it off. I've heard that it's some kind of encryption tool for my Windows device, but I'm not entirely sure what it does or if I really need it. I'm trying to optimize my system's performance, and I'm wondering if disabling BitLocker could help with that. What do you think? Is it SAFE to turn off BitLocker, or should I keep it on for security purposes?