ARM's TrustZone is a security technology integrated into many ARM processors. It creates a secure environment within the device, allowing sensitive data and applications to run separately from the regular operating system. This separation helps protect against unauthorized access and potential threats. TrustZone divides the system into two worlds: the secure world and the normal world. The secure world handles critical tasks, such as managing encryption keys and secure transactions, while the normal world runs standard applications. This architecture enhances overall device security, making it harder for attackers to compromise sensitive information.