In this post, we will learn the difference between Tree and Graph in Java. This is a frequently asked

question in Java interviews for beginners. Let's dive into it.

question in Java interviews for beginners. Let's dive into it.

Tree | Graph |
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A Tree is a special kind of graph where there are no cycles, i.e., it is acyclic. | A Graph is a more general structure compared to a tree. It can contain any number of nodes (also called vertices) and edges, including cycles. |

In a tree, there is always a unique path from the root node to any other node. | In a graph, there can be multiple paths between two nodes. |

Trees have a hierarchical structure with a definite parent-child relationship. | Graphs may not necessarily have a hierarchical structure and can have complex relationships. |

All trees are connected and they always have a root node. | Graphs can be disconnected and they do not necessarily have a root node. |

A tree has N-1 edges where N is the number of nodes. | In a graph, there is no such relationship between the number of edges and vertices. |

Trees do not contain self-loops. | Graphs may contain self-loops (an edge that connects a vertex to itself). |

A tree is an undirected graph. | A graph can be either directed (edges have direction) or undirected. |

A tree has a clear flow of control from top to bottom. | Graphs do not have a clear flow of control, the control can traverse any path. |

Trees are used in areas like hierarchy representation, XML/HTML parsing, routing algorithms etc. | Graphs are used in areas like social networks, web page link mapping, location/routing algorithms etc. |