# Graph Data Structure - Variants or Types or Kinds

In this page, we will learn about various types or kinds of graph.

### Graph Variants or Types of Graph

**Directed Graph (or) Digraph**: It is graph in which each edge has a direction to its successor.

**Undirected Graph**: It is a graph in which there is no direction on the edges. The flow between two vertices can go in either direction.

**Weighted Graph**: If the graph has a some cost or weight on the edge, then we say that graph is said to be a weighted graph. Weight can be applied in both Directed and Undirected graph.

**Unweighted Graph**: If there is no cost or weight on the edge, then we say that graph is an Unweighted Graph. For example, Figure 2 is the Unweighted Undirected graph

### Based on How Connected the Graph is

**Strongly Connected Graph**: If there is a path from each vertex to every other vertex in the directed graph, then only we say that directed graph is said to be Strongly connected graph.

**Weakly Connected Graph**: If there are at least two vertices that are not connected, then we say that directed graph is said to be weakly connected graph.

**Disjoint Graph**: The graph is a disjoint, if it is not connected.

**Complete Graph**: If there is an edge between every pair of vertices, then we say that graph is said to be complete graph.

### Acyclic Graph

A graph is acyclic if it has no cycles.

**Directed Acyclic Graph**: A directed acyclic graph is directed graph without any directed cycles. Referred by its short name **DAG**

### PolyTree

PolyTree is a directed graph without any undirected cycles

### Forest

Forest is a undirected graph without any cycles