Transport Requests are 4 types.
1) Customizing requests :
Changes to Customizing settings are recorded in
Customizing requests.
2) Workbench requests :
Workbench requests record changes made to ABAP Workbench
objects.
3) Transport of Copies :
Transports of copies allow you to transport (sub-)objects
in an object list into any other SAP System you want.
4) Relocations:  |