Data Table methods control UFT's interaction with the data table. You can set the active row to read from, advance backward and forward through the data table, add parameters on the fly, and import and export data to and from the data table.

Environment variables are set in the Advanced settings of your Window's computer. Things like the Java home path, license server path, etc. are stored there. They are like 'global' variables that can store information that UFT and other applications can read from.