DFSORT IS IBM’S PRODUCT AND SYNCSORT IS PRODUCT OF SYNCSORT COMPANY.
The basic functions of both are almost same like SORT,MERGE,COPY and other benefits.
ICETOOL is the utility for DFOSRT.
SYNCTOOL is in the same way a tool for SYNCSORT.
For getting syncsort manual you need to give the licensed CPU serial number. DFOSRT manual is freely available.
The easiest way to know if your z/os supports syncsort or dfsort is to look at the messages in sysout for the SORT step.
DFSORT message begins with ICE*
SYSNCORT message begins with WER*.