- The document demonstrates various commands for exploring and summarizing data in R such as the iris data set including head(), tail(), str(), class(), summary(), and $-operator. - The iris data set contains measurement data for 150 flowers across 4 variables and is stored as a data frame object in R. - Data frames allow storing different data types together and can be explored using commands like summary() which provides summaries tailored to each variable type. - Matrices can also be used to store multi-dimensional data and various functions like dim(), apply(), and cbind() allow manipulating the dimensions and combining matrices.