Charts are what we call graphs in math class.
Charts are visual representations of worksheet data. Charts often makes it easier to understand the data in a worksheet because users can easily pick out patterns and trends illustrated in the chart that are otherwise difficult to see.
Different types of charts serve different purposes.
Pie Charts -- are used to show percentages. For example, a pie chart could be used to show what percentage of your total daily calorie intake is represented by one quadruple cheese and bacon hamburger.
Column Charts -- are used to show comparisons between items of data. Each column in the chart represents the value of one item of data. An example of this would be to compare the calories in a quadruple cheese and bacon hamburger with the calories in a glass of water and a bowl of beet greens.
Bar Charts -- are very similar to column charts, except they run horizontally on the page instead of vertically like column charts.
Line Charts -- are used to show trends over time. Each line in the graph shows the changes in the value of one item of data. For example you could show changes in your weight over a period of months as a result of eating a quadruple cheese and bacon hamburger every day for lunch.