generally, when we want to convey something to others, we make use of words / verbal statements.
in court, if u verbally tell something to the court, ur words vanish in air. There is no record of verbal things. at a later stage of the litigation, u can not SHOW ur VERBAL WORDS to anyone and there is no proof to what u said.
remedy :
therefore, a purshis is a way to tell something / anything to the court in written format.
in short,
purshish = a simple paper, on which u write what u want to tell the court & stick a court fee stamp of rs. 5/-
such purshish can be exhibited and read in evidence.
however, understand that u can not put forth any prayer in a purshish. u can furnish only information.