SL (Stop Loss): If you bought a stock at 112 and you want to limit your losses to 102
which is 10 points. So if the markets come’s against you your order
should ideally get squared off at 102.
SL-M (Stop Loss Market): Now with the same example what if the market crashes and passes your SL of 102 but does not execute can leave your SL order pending? this can
happen if we have sudden fall. So to avoid these situations we use SL-M
and keep a trigger price which is 102. Now even if the markets fall by a
margin the order will get executed 102 or below.
JUST Read it.