text: communicate different types of information. Some 
  charts show simple relationships between values, 
  while others are designed for quite technical 
  purposes. Here is a summary of the use of different 
  chart types. 
  
  **Column, Bar**
  
  These chart types, either in 2D or 3D, are used to 
  compare values across categories. For example, 
  they could compare the populations of different 
  countries. 