Difference Between X & Y Group: Indian Air Force Recruit Candidates for their different trades divided as technical-needed to maintain various technical items or machines of Indian Air Force and Non- technical for providing support services to keep these machines well and active. The technical trade is also termed as ‘X’ group and Non-technical as ‘Y’ group.  These X & Y group candidates are called Airmen or PBOR i.e. Persons below officer rank. Male candidates of Science stream in Class 12th i.e. Physics and Mathematics can apply for X group and Male candidates of any stream in 12th class can