How does a stoploss works actually?

What I mean to ask is suppose I bought SBIN at 292 and also put a stoploss order at 291.5. Is this stoploss order a sell order. Does it gets to the Offers column in market depth. That means if while buying at 292 I simultaneously place stop loss at 291.5 then just after that someone else places a limit order at 291.5 so will my stoploss order get hit? Or is it just like if the market boila down slowly slowly to 291.9 then 291.8 and so on till 291.8 and then my 291.5 sl gets hit. How is the working?

it is practically a sell order but the order will get executed only the market reaches that price point. it will not be executed if someone places a limit order. actually the order is not placed simultaneously. you have to put a trigger price and a limit price or you can put a trigger price and a market order. your sell order through stoploss will get placed only when market reaches your trigger price.