What is the difference between order by and sort by in hive?

• SORT BY will sort the data within each reducer. We can use any number of reducers
  for SORT BY operation.
• ORDER BY will sort all of the data together, which has to pass through one reducer.
  Thus, ORDER BY in hive uses single reducer.
• ORDER BY guarantees total order in the output while SORT BY only guarantees
  ordering of the rows within a reducer. If there is more than one reducer, SORT BY may give partially ordered final results