From the equation, you can derive a series of rates of change one one variable with respect to another, often colloquially known as "the greeks", since they're all denoted with greek letters.

The first one to know is delta. It's the rate of change in the option's price with respect to the underlying asset's price.

Delta generally follows a curve, not a straight line. Gamma is the rate at which delta changes with respect to the underlying asset's price.

The reason why these are a big deal are because options traders often try to remain "delta-neutral" - they want the overall delta of their options portfolio to remain close to zero, which limits the effect of fluctuations in the underlying asset's price on the overall value of their portfolio. But that's a constant balancing act, because changes in the underlying asset price also change the delta of their position. A low gamma means that it changes slowly, and it's easy to keep things balanced. A high gamma means that they're sitting on an unstable equilibrium, and they're going to have to buy and sell more aggressively in order to maintain their position.