Data is a large set of numbers, to understand them better we represent them pictorially to analyze, compare, arrive at deeper insights that can help in decision making, research etc.
Tally chart / frequency chart , Pictograph, Bar graph , Double bar graph , Histogram , Pie chart are few forms of representing data.
Lets understand data representation with some simple demonstration:
Shilpa was sitting at the side of the road waiting for her bus. While she waited she recorded the colour of 200 cars that drove past her. Below is a pie chart showing the number of each color cars that drove past shilpa.