Level 1B is raw data used by entities such as the U.S. Navy, insurance underwriters and a wide range of commercial ventures who run their own algorithms to predict conditions.
Level 2 data provides dense, three-dimensional data sets of temperature, pressure, and water vapor from where the instrument was scanning. In time, we will produce a fundamental data set of the entire earth in less than an hour. The earth, a country, a coastline and, very nearly, a neighborhood.
Level 3 data is derived from Level 2 data to produce other types of information such as wind and trace gas concentrations.