SAR vs. stock option payoff

CFA Level II
#1

I am still confused on the difference in the compensation expense between the two.

From what I understand the SAR compensation is based upon a straight cash outlay, however, I am still confused on how the compensation for stock option is actually done

#2

Stock options are based on the option value and spread over the vesting term.

#3

Ok, and the service period occurs before the vesting term, correct?