A linked list is a linear data structure where each element, called a node, contains two parts: the data and a reference (or pointer) to the next node in the sequence. Linked lists differ from arrays in that they do not store elements in contiguous memory locations. Instead, each node is dynamically allocated, and nodes are linked through pointers, making linked lists flexible and efficient for certain operations like insertions and deletions.

Definition: A linked list is a linear data structure where each element (node) contains data and a reference (pointer) to the next node in the sequence. It allows dynamic memory allocation.

Linked lists come in various types:

1. Singly Linked List: Each node points to the next node, with the last node pointing to null.
2. Doubly Linked List: Each node has two pointers, one pointing to the next node and one pointing to the previous node.
3. Circular Linked List: The last node points back to the first node, forming a loop.

Linked lists are ideal for scenarios where the size of the data structure may change dynamically, as they allow for efficient insertions and deletions without requiring a contiguous block of memory. However, accessing elements in a linked list is slower compared to arrays, as it requires traversing the list from the head node.