Sammy was stabbed by Jake in season two episode 21 all hell breaks loose part one. He was ressurected through dean selling his soul to the crossroads demon in episode 22 all hell breaks loose part two!
sam died in seson 2 episode 21 ALL hell Breaks Loose (part one) by JAKE WHO WAS TOLD BY YELLOW EYED DEMON TO KILL SAM. And he was brought back to life by Dean who sold his life for he's in seson 2 episode 22 All Hell Breaks Loose
(part two)
The main time Sam died - and the one shown in the picture - was in season 2 episode 21, All Hell Breaks Loose Part 1. He's brought back to life by Dean's deal the next episode, All Hell Breaks Loose Part 2.
Sam's also died and been brought back to life in Wishful Thinking and in Dark Side Of The Moon.
Sam died in Season 2 all hell breaks loose part 1 but in all hell breaks loose part 2 he was brought back to life because Dean sold his soul to a cross roads demon.