A linked list is a fundamental data structure in Python that consists of a sequence of nodes. Each node contains a data value and a reference (or pointer) to the next node in the sequence. This structure allows for efficient insertion and deletion of elements, especially when the number of elements is unknown, as it does not require contiguous memory allocation like arrays do ¹².

In Python, linked lists can be implemented using user-defined classes. Typically, you would create a Node class to represent each element in the list, which includes properties for the data value and a reference to the next node. Additionally, a LinkedList class is created to manage the nodes, starting with a head node that points to the first element ²³.

There are two main types of linked lists: singly linked lists, where each node points only to the next node, and doubly linked lists, where each node points to both the next and the previous nodes. This flexibility allows linked lists to be used in various scenarios where dynamic data management is required ²⁴.