A package to manage R-like data frames. A DataFrame is a table where columns are variables and rows are measurements. For example: Each column correspond to a variable. Each variable can have a different type. In this case, room is a string, wifi is an array of numbers, and acceleration is a number. In JSON: A DataSet is a collection of DataFrame files. All files must have the same schema. The API provides methods to iterate over the DataSet which hides teh details about files from the end user.