If you measure `n` variables (each of a different type) of a single object, then you get a table with `n` columns for each object row. If there are `m` observations, then we have `m` rows of data. For example, given the student grades as data, you might want to know `compute the average grade for each socioeconomic group`, where `grade` and `socioeconomic group` are both columns in the table, and there is one row per student.

`DataFrame` is the most natural representation to work with such a (*m x n*) table of data. They are similar to Pandas `DataFrames` in Python or `data.frame` in R. `DataFrame` is a more specialized tool than a normal array for working with tabular and statistical data, and it is defined in the `DataFrames` package, a popular ...