Explain the difference between an internal and an external sort, the pros and cons, internal sort syntax

Explain the difference between an internal and an external sort, the pros and cons, internal sort syntax etc? 
An external sort is not COBOL; it is performed through JCL and PGM=SORT. It is understandable without any code reference. An internal sort can use two different syntaxes: 1.) USING, GIVING sorts are comparable to external sorts with no extra file processing; 2) INPUT PROCEDURE, OUTPUT PROCEDURE sorts allow for data manipulation before and/or after the sort. 

Answer:
1. Internal sort is used in COBOL application prog while external sort is used in JCL.

2. Internal sort uses workfiles while external sort uses the DFSORT mechanism.

3. External sort is more complicated than internal sort.

4. Internal sort is more flexible as we can alter or update data before  and after performing internal sort whereas the same doesn't hold true for external sort.