cdrs

CDRs is an acronym that can refer to several concepts in different fields. The two most common are Call Detail Records in telecommunications and complementarity-determining regions in immunology. The exact meaning depends on the context, so readers should consider the subject area when encountering the term.

Call detail records (CDRs) are data entries created by telephone switches and other network elements that document details of communications transactions. A CDR typically includes information such as the origin and destination numbers, start time, end time, duration, call type, and routing or signaling data. These records are used for billing, network planning and optimization, usage analytics, fraud detection, and law enforcement requests. Privacy and data protection laws regulate access to CDRs, retention periods, and the handling of personally identifiable information. In practice, organizations implement retention policies and access controls to balance service delivery, business needs, and legal requirements.

Complementarity-determining regions (CDRs) are short, hypervariable loops within the variable domains of antibodies and T-cell receptors that determine antigen-binding specificity. Each immunoglobulin or receptor variable domain contains three CDRs on the light chain (L1, L2, L3) and three on the heavy chain (H1, H2, H3), with the six CDRs collectively shaping the antigen-binding site alongside framework regions that provide structural support. CDR diversity results from somatic recombination and somatic hypermutation. In biotechnology and therapeutic development, CDR sequences are central to antibody discovery, humanization, and engineering.