• A property of an object whose state cannot be modified after it was created (an immutable or unchangeable object). This is in contrast to a mutable object. In some cases, an object is considered immutable even if some internally used attributes change, but the object’s state appears to be unchanging from an external point of view. Strings and other concrete objects are typically expressed as immutable objects to improve readability and runtime efficiency in object-oriented programming. Immutable objects are also useful because they are inherently thread-safe. ← Wikipedia

1. More about this term: Web search, articles and videos, books
2. Previous term: Immediately Invoked Function Expression
3. Next term: Imperative programming
4. Random term: Web Platform Baseline