A single linked list is a data structure that consists of a sequence of elements, called nodes. Each node contains two parts: the data it holds and a reference, or pointer, to the next node in the sequence. This allows for efficient insertion and deletion of nodes, as these operations can be performed without reorganizing the entire structure. In a single linked list, the first node is known as the head, while the last node points to null, indicating the end of the list. This structure is commonly used in programming for tasks that require dynamic memory allocation and flexible data management.