LSMW is widely used by EDI programmers. EDI Programmers connect the SAP system to Non SAP system. During this Data migration is a necessity. When data migrates from source to destination the destination code is differrent from the source code. So what LSMW does is
* Converts the data in to batch files
* Then converts the batch files in to source code batch files
* And then mirgates data. Standard Interfaces like BAPI or Idoc are used in this process.