Direct graph.

• A graph is a pictorial representation of a set of node where some pairs of nodes  are connected by links. 
• The interconnected objects are represented by points termed as vertices, and the links that connect the vertices are called edges.

Basic Operations: 

• Add Vertex − Adds a vertex to the graph.

• Add Edge − Adds an edge between the two vertices of the graph.

• Display Vertex − Displays a vertex of the graph. Some of the  Advantage of direct graph. 
• Graph can be created proportionally to the quantity it needs to represent
• Displays multiple classes of data in one chart
• Puts large sums of data into visual form for easy understanding
• More visually appealing than other graphs
• Offers easy calculations of data accuracy
• Requires little explanation
• Understood easily by different departments within a business and for media purposes.                    Disadvantages of direct graph
• Doesn't reveal exact values
• Multiple graphs are needed for time-lapse data
• Key assumptions, causes, effect, and patterns are not revealed
• Manipulated easily, causing false impressions or interpretations.