Given name, surname, Middle name for GRE, USMLE

There has been a lot of confusion while applying for GRE, USMLE regarding the Given name, surname, Middle name.
I have these two links of blogs which makes the things clear. Hope it helps you people.

http://www.happyschoolsblog.com/lastname-passport-transcripts-gre-application/

http://www.happyschoolsblog.com/given-name-vs-surname-passport-india/