# Graph

In graph theory, a graph, also called a network, is a collection of points together with lines that connect some subset of the points.

Graph is a college-level concept that would be first encountered in a discrete mathematics course covering graph theory.

### Examples

Complete Graph: | A complete graph is a network in which every pair of vertices is connected by an edge. |

Connected Graph: | A connected graph is a network for which there is a path between any pair of vertices. |

Cycle Graph: | A cycle graph is a network containing a single cycle which passes through all its vertices. |

Directed Graph: | A directed graph is a network in which each edge is specified as going in a particular direction. |

Planar Graph: | A planar graph is a network that can be drawn in a plane without any edges intersecting. |

Polyhedral Graph: | A polyhedral graph is a network made up of the vertices and edges of a polyhedron. Polyhedral graphs are always planar. |

Tree: | A tree is a network that contains no cycles. |

### Prerequisites

Function Graph: | A function graph is a set of points showing the values taken by a function. This type of plot is called simply a "graph" in common parlance, but is distinct from a collection of points and lines (also called a network) that mathematicians refer to when they speak of a "graph." |