The Lesson
Data is a set of facts (such as numbers, measurements or words) that have been collected or measured. Data can be reported, visualized and analyzed to help us learn and make decisions.Dictionary Definition
The MerriamWebster dictionary defines data as "factual information (such as measurements or statistics) used as a basis for reasoning, discussion, or calculation."Real Examples of Data
When we want to understand something about the world, we collect data about it.
Imagine a teacher wanted to find out about how well a mathematics class is doing. The teacher would collect the classes' test scores:
The test scores are data. 
Imagine you wanted to know the typical heights of people. You could measure the heights of people.
The heights are data. 
Imagine you wanted to know how many of each shape you had. You could observe which shapes you have.
The shapes are data.
Types of Data
There are different types of data.
The main distinction is between qualitative
(words) and quantitative (numbers) data.
 Test scores and the heights are both quantitative data (because we use numbers to describe them).
 Shapes are qualitative data (because we use words to describe them).

There are also two types of quantitative data: discrete and continuous data.
 Discrete data can only take certain values, like whole numbers (1, 2, 3...). Discrete data can (often) be counted. Test scores are discrete data. Test scores can only take whole numbers.
 Continuous data can take any value (within a range). Continuous data can (often) be measured. Heights are continous data. A person could be 5 feet and 9½ inches. They don't have to be a whole number of feet or inches.
Using Data
Data can be summarized using averages:Data can also be presented in tables and graphs: