Crash is not profitable over time, whatever system a player follows. Every multiplier carries the same built in edge, usually one to five percent, so cashing out early wins often but small, and waiting for large multipliers wins rarely. Anyone asking how to win at crash is really asking how to lose slowly: a fixed cash out point and a fixed budget keep a session short, but they cannot put the house edge in the player's hands.
Plinko is a game in which a ball drops through rows of pegs and lands in a slot along the bottom, each slot paying a fixed multiple. It borrows the board from a television prize game and looks like pachinko, but the two are not the same: pachinko is a machine game of its own, while online plinko boards are drawn on screen. The payout table does not change during the drop, and the random result picks the slot.
Crash gambling works on a multiplier that climbs from one and stops at a random point. To play, a player places a bet before the round, then chooses when to cash out; leaving before the crash pays the stake times the multiplier reached, staying too long loses it. The crash point comes from an algorithm that many sites publish as provably fair, so any round can be checked afterwards. No betting strategy changes where the next crash lands.