Graphs are an essential data structure in computer science for modeling networks. Let’s review some key terms:

• vertex: A node in a graph.
• edge: A connection between two vertices.
• adjacent: When an edge exists between vertices.
• path: A sequence of one or more edges between vertices.
• disconnected: Graph where at least two vertices have no path connecting them.
• weighted: Graph where edges have an associated cost.
• directed: Graph where travel between vertices can be restricted to a single direction.
• cycle: A path which begins and ends at the same vertex.
• adjacency matrix: Graph representation where vertices are both the rows and the columns. Each cell represents a possible edge.
• adjacency list: Graph representation where each vertex has a list of all the vertices it shares an edge with.