What data types are considered immutable in most programming languages?

In most programming languages, immutable data types are those whose values cannot be changed after creation. In Python, they include:

• Numbers (int, float, complex)
• Strings (str)
• Tuples (tuple)
• Boolean values (bool)
• Frozensets (frozenset)

For example, a string cannot be changed: any operation creates a new string rather than modifying the existing one.

s = "hello"
s = s + " world"  # a new string is created, the original remains unchanged

This is important for data security and optimization, as immutable objects can be used as keys in dictionaries and elements of sets.