A call-detail record (CDR) is an operational telecom log about a call or other communication. It may include the numbers involved, timestamps, duration, call status, and network fields. A CDR records metadata, not the conversation’s audio or message content.
CDRs help providers operate and bill for services, troubleshoot networks, and investigate service issues. In security and privacy, accumulated records matter because contact patterns and timing can reveal relationships, routines, or possible location clues. Defenses include limiting collection, setting justified retention periods, controlling access, and verifying deletion across backups and related systems. Encrypted communications can protect content without hiding metadata that a carrier records.