Immutable Data

overview

Summary

Immutable data refers to values or structures that cannot be changed after they are created. Instead of modifying data in place, new versions are produced for any update. This model improves predictability, thread safety, and reasoning about programs, and it underpins functional programming and persistent data structures. Trade-offs include potential memory churn and copying overhead, which are mitigated by techniques like structural sharing and copy-on-write.