immutable ↔ (of entity/variable) content cannot be altered

Value of Primitive is immutable unlike the variable assigned to it

a primitive can't be directly altered however it can be replaced

contrast with

mutable

mutable

(typeof) Variable that can be changed

References

1. symbol ↔ immutable constant Primitive Value to rep unique Object property keys

2. Value ↔ immutable data saved at Memory Address

3. blob ↔ file-like object of immutable raw data

4. React Element ↔ immutable stateless building blocks of React apps, returned by components

5. Object.freeze() ↔ Object Static Method to make Object immutable

6. Docker Container Image ↔ immutable snapshot of Software & Deps-tree down to OS-layer (everything req to run App)