pls tell me what is ULIP plan,, ?

i hav no idea bout it, some 1 suggested to me from the birla sun life insurance,, what will happen if i pay the 3 premiums , 1 per annum
hw much will i get after three years????
is it related to the condition of the market???
suppose i pay 6000rs as premium
should i finish it when market is at its peak??
pls gv a genuine advice