In Python, special methods, also known as magic methods or dunder methods (due to their double underscore prefix and suffix), are predefined methods that enable customized behavior for classes. These methods are invoked implicitly by Python in response to specific operations or behaviors, such as object instantiation, attribute access, comparison, and arithmetic operations. Examples of special methods include `__init__` for object initialization, `__str__` for string representation, `__len__` for determining the length of objects, and `__add__` for defining addition behavior. By implementing these methods within a class, developers can customize how instances of the class behave in various contexts, making Python classes more flexible and intuitive to use. Special methods are fundamental to Python's object-oriented programming paradigm and are extensively used in defining custom data types, iterators, and operator overloading.