A pickled object is a Python object that has been serialized using the pickle module. Pickling converts a Python object hierarchy into a byte stream, which can be saved to a file or transferred across a network. The pickled object can later be unpickled or deserialized to recreate the original Python object. The pickle module allows you to work with various Python objects, including built-in data types (such as integers, strings, lists, dictionaries), custom objects, functions, and more. It supports the serialization and deserialization of complex object hierarchies, preserving their internal structure and state.