Mathematics is the language of science, and data is one of the founding pillars of science. So, of course maths would have the means to handle data and convert it into meaningful and comparable outputs.
Anything that can be grouped based on certain comparable parameters can be thought of as Data.
What are parameters? Parameters define the context in which the comparisons made between objects are to lie and are to be quantified.
A data set is what allows us to compare and contrast the information given regarding a particular group and come up with meaningful interpretations and conclusions.
Data Handling is the process of gathering, recording and presenting information in a way that is helpful to others.
Data is usually represented in the form of pictographs, bar graphs, pie charts, histograms, line graphs, etc.
This is how a pictograph looks.
This is how a bar graph looks.
This is how a pie chart looks.
This is how a histogram looks.
This is how a line graph looks.