What is an each way bet, in short
Weighing both sides of "What is an each way bet?" leads to one event. Hedging and arbitrage both mean betting on more than one side of the same event. A hedge does it after a first bet is already placed, to lock in part of a win or cut a loss. Arbitrage does it at the start, across different books whose prices disagree, so that every outcome returns a little more than the total stake. What they share is the arithmetic of splitting stakes between results on opposite sides.