TopA graph is basically a physical representation of given data. It is drawn from Combination of the vertices or from the combination of nodes. A graph can be of any of the following type like: Area Graph, Line Graph, Double line Graph, Bar Graph, Exponential Graph, Waterfall Graph, Staircase Graph, Polar Graph etc. Now the question arises how to explain a graph, for this let us take a small example. Let us consider a double line graph as shown below:
In this graph we can see one horizontal line which is x – axis and one perpendicular line which is y - axis. The Point marked on horizontal line indicates the subjects that are Maths, English, Hindi and Science. On y - axis we have marks obtained by two students named Tam and Rock. The marks are out of 5. The marks are ranging from 0 to 5, the scale is taken as 0.5 units. The two lines drawn between two horizontal and Perpendicular Lines indicate the marks obtained by both students. Red Line indicates the marks obtained by Rock and Blue line indicates the marks obtained by Tam.
Red and blue lines can be used to compare the marks obtained by both candidates.
For Example: Tam obtained 4.5 marks in science and Rock obtained 2.7, means Tam scored higher than Rock. Similarly, Rock scored 4.5 in English and Tam scored 2.5, here Tam scored less marks than Rock. So, this means from these two lines in a graph we can compare the marks of as many students we want by just coding the Students marks from respective colors. So, we can easily say that a graph is a good way to make analytical representation of data.