A dictionary in Python is a built-in data type that stores data in key-value pairs. Dictionaries are mutable, which means they can be changed after they are created. Keys in a dictionary must be unique and immutable (e.g., strings, numbers, or tuples), while values can be of any data type and can be duplicated. Dictionaries are defined using curly braces {}, with key-value pairs separated by colons : and items separated by commas ,
