A cyclic graph is a type of graph in data structures where there exists at least one path that starts and ends at the same vertex. In other words, a cyclic graph contains one or more cycles.

## What is a Graph?

Before diving into cyclic graphs, let’s first understand what a graph is. In computer science, a graph is a collection of nodes (or vertices) connected by edges. It is used to represent relationships between objects or entities.

### Types of Graphs

There are two main types of graphs:

**Directed Graph:**Also known as a digraph, it consists of vertices and directed edges. The edges have a specific direction, indicating the relationship between the nodes.**Undirected Graph:**In contrast to directed graphs, undirected graphs have edges that do not have any specific direction. The relationship between the nodes is symmetric.

### Cyclic Graphs

A cyclic graph contains cycles. A cycle in a graph is a path that starts and ends at the same vertex, without passing through any other vertex more than once.

In simple terms, imagine you are walking on the graph starting from one node and following the edges. If you can return to the starting node by traversing various nodes without repeating any node, then the graph contains a cycle.

### Detecting Cyclic Graphs

Detecting whether a given graph contains cycles can be done using various algorithms like Depth-First Search (DFS) or Breadth-First Search (BFS).

__Depth-First Search:__ This algorithm explores each branch of a given path until it either reaches the end or finds a cycle. By keeping track of visited nodes, we can detect cycles.

__Breadth-First Search:__ Similar to DFS, BFS explores all the vertices in a graph but does so by visiting vertices in layers. If we encounter a previously visited vertex during BFS, it indicates the presence of a cycle.

### Applications of Cyclic Graphs

Cyclic graphs have various real-world applications. Some notable examples include:

- Modeling transportation networks
- Representing dependencies between tasks in project management
- Analyzing social networks and relationships
- Solving scheduling problems in computer science

## Conclusion

In summary, a cyclic graph is a graph that contains at least one cycle. It is an essential concept in data structures and has numerous applications in various domains. Detecting cycles in graphs can be done using algorithms like DFS or BFS.

Understanding cyclic graphs is crucial for solving complex problems involving relationships and dependencies between entities or objects.