A linked list is a collection of nodes, each made up of a reference and a value. Nodes are strung together into a sequence using their references. Linked lists can be used to implement more complex data structures like lists, stacks, queues, and associative arrays.
LinkedHashMap class is Hash table and Linked list implementation of the Map interface, with predictable iteration order. It inherits HashMap class and implements the Map interface.
The important points about Java LinkedHashMap class are: A LinkedHashMap contains values based on the key. It contains only unique elements. It may have one null key and multiple null values. It is same as HashMap instead maintains insertion order.