Gurfatehji,
kh@ls@ ji has explained very correctly. Please allow me to express my opinion as under :
Simran : remembering the lord almighty.
need of simran : we are only fulfilling our promise to the lord whilst still in mother's womb, that "lord please let me out of this hell and i will remember you always".
method of simran : this, according to one's preference, could be verbal, silent though i prefer it going on in the anaahad even while we are at work.
mental status of meditators : elation whereby they are always surrounded by an eternal bliss.
types of meditation : still need to find out for myself. If anyone knows, please enlighten me.