What do 'do re me fa so la ti do' represent?

Answer 1

Solfege names for the various pitches of each major scale. You can also add sharps and flats to create the chromatic solfege scale (Do, di, re, ri, mi, fa, fi, sol, si la, li, ti, do, ti, te, la, le, sol, se, fa, mi, me, re, ra, do)

You add an "i" suffix to the end of each normal pitch to indicate that it is "sharp".

And you add an "e" suffix to indicate that it is "flat" (except "re" which becomes "ra", since it already ends in "e")

It is used frequently in vocals and ear training