A security feature developed by Microsoft for Windows operating systems, designed to provide full disk encryption. BitLocker safeguards the data on hard drives and other storage devices by encrypting the entire volume, rendering the data inaccessible to unauthorized users. It primarily protects against data theft or exposure on lost or stolen computers and can be used in conjunction with a Trusted Platform Module (TPM) for enhanced security. BitLocker is available in various editions of Windows, including Windows Vista, 7, 8, 8.1, and 10, as well as Windows Server versions.