# What Is Edge List Data Structure?

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Heather Bennett

The Edge List data structure is a fundamental concept in computer science and graph theory. It provides a way to represent the edges or connections between nodes in a graph. In this article, we will explore the Edge List data structure, its properties, and its applications in various fields.

## What is a Graph?

Before diving into the Edge List data structure, let’s briefly understand what a graph is. A graph is a collection of nodes or vertices connected by edges or arcs.

It is a versatile data structure used to represent relationships between objects. Graphs are commonly used in various domains such as computer networks, social networks, transportation systems, and more.

## The Edge List Data Structure

The Edge List data structure represents the connections between nodes in a graph using a list of edges. Each edge consists of two vertices or nodes that are connected. Here’s an example of an edge list:

```(A, B)
(B, C)
(C, D)
```

In the above example, we have three edges connecting four nodes: A to B, B to C, and C to D.

### Properties of Edge Lists

The Edge List data structure has several important properties:

• Simple Representation: The edge list provides a simple representation of connections between nodes by listing all the edges sequentially.
• No Duplicate Edges: Each edge appears only once in the edge list. If there are multiple edges between two nodes, they can be represented separately.
• No Implicit Nodes: The edge list does not explicitly store information about individual nodes; it only focuses on storing connections.

### Applications of Edge Lists

The Edge List data structure finds applications in various domains. Some notable applications include:

• Graph Algorithms: Many graph algorithms utilize the edge list representation, such as breadth-first search (BFS), depth-first search (DFS), and Dijkstra’s algorithm.
• Social Networks: Edge lists are commonly used to represent relationships between users in social networks, enabling features like friend suggestions and network analysis.
• Routing Algorithms: In computer networks, edge lists are used to represent connections between routers, helping in efficient routing of data packets.

## Conclusion

The Edge List data structure is a simple yet powerful way to represent connections between nodes in a graph. It provides a concise and efficient representation for various graph-related applications and algorithms. Understanding the edge list is crucial for anyone working with graphs or interested in graph theory.

In this article, we explored the Edge List data structure, its properties, and its applications in different fields. Now that you have a solid understanding of the edge list, you can confidently apply it to solve graph-related problems and dive deeper into advanced graph algorithms.