A Trusted Execution Environment (TEE) is a secure area within a computer’s main processor that ensures sensitive data and critical operations are protected from unauthorized access, even if the main operating system is compromised. TEEs isolate confidential information, such as encryption keys or biometric data, and run trusted applications in a controlled environment. This hardware-based security approach helps prevent hackers and malware from accessing or tampering with sensitive processes, making TEEs essential for secure computing in devices like smartphones, servers, and IoT devices.