BitLocker is a full disk encryption feature included with Windows operating systems. It was first introduced in Windows Vista and is designed to protect data by encrypting the entire hard drive. This ensures that even if a laptop or computer is lost or stolen, the encrypted data remains inaccessible to unauthorized users.
bitlocker2john.exe appears to be an executable file related to BitLocker. Specifically, it seems to be associated with a tool that can be used to extract BitLocker recovery information. The "john" part in the filename might imply a connection to John the Ripper, a password cracking tool.