A Spread is basically any type of Options contract involving two legs on either side i.e., Buy and Sell which have different strikes & expiry time frames - e.g., Bull Call Spread or Bear Put Spread where each “leg” has its own unique execution price. On the other hand, Option Spread signifies strategies constructed using various combinations correlating futures & available/listed instrument pricing models i.e., creating Payoff profiles using combination formulae from specified risks parameters like Delta etc.