Linked lists are a fundamental data structure in computer science, consisting of a sequence of nodes where each node contains data and a reference (or pointer) to the next node in the sequence. Unlike arrays, linked lists do not require contiguous memory allocation, allowing for dynamic memory usage and efficient insertions and deletions. The first node in a linked list is known as the head, while the last node points to null, indicating the end of the list. Linked lists can be singly linked, where each node points to the next, or doubly linked, where nodes point to both the next and previous nodes, enhancing traversal capabilities.