# Linked Lists

by Eddie Huang##### A Brief Intro to Graph Notation

Graphs consist of a set of `nodes`

(also known as `vertices`

) and `edges`

that form connections between nodes.

##### Linked Lists

Linked lists are ideally used to store information that require some sort of order to them.
A linked list is a special type of graph where the nodes and edges form a chain-like structure.
The nodes at the end contain only one edge, while the internal nodes contain two edges (one incoming and one outgoing edge).
The first node is called the `head`

and the last node is called the `tail`

.

There are two main types of linked lists:
singly linked lists and doubly linked lists. In a singly linked list, there only exist *forward* edges
(i.e. edges only connect from one node to the next node in the list). In a doubly linked list, there exist both *forward* and *back*
edges.