TrueCrypt is an open source software to encrypt volumes of data. It even supports the creation of virtual encrypted volumes which is portable. Developed by TrueCrypt Foundation
License: Open Source
BitLocker is a full disk encryption feature included with Windows Vista and later. It is designed to protect data by providing encryption for entire volumes. By default, it uses the AES encryption algorithm in cipher block chaining (CBC) or XTS mode with a 128-bit or 256-bit key. Developed by Microsoft
License: Commercial
TrueCrypt is an open-source encryption tool that offers greater flexibility and cross-platform support, but it is no longer maintained. BitLocker, on the other hand, is a user-friendly encryption tool integrated into Windows, providing seamless operation but is limited to Windows systems and raises concerns about proprietary software.