How do immutable data types differ from those that use hashing?

Immutable data types are those whose values cannot be changed after creation. Examples include strings and tuples in Python.

Data types that use hashing are usually required to be immutable so that their hash code remains constant. This is important for the correct functioning of hash tables, such as dictionaries or sets.

Thus, the main difference:

• Immutability guarantees that an object will not change after creation.
• Hashability requires immutability so that the object can be used as a key in a dictionary or as an element in a set.

Example: a string in Python is immutable and hashable, whereas a list is mutable and cannot be used as a dictionary key.