Delta is for Difference.
Gamma is for Gambling (speculation)
Theta is for Time Decay
The most important Greek is likely Delta. It tells you how closely the option or option spread behaves like the underlying stock. It also provides a good estimate of what the probability is that the stock price will touch the strike price…. that’s a nifty little shortcut.
Here is a great way to remember the greeks and a short explanation of each:
Delta is the Difference you would see in the options price with a $1 move in the underlying stock.
Gamma is for the Gambling. I.e. if you are long gamma then you are gambling in hopes that the stock will move a lot and if you are short gamma you are gambling that the gamma doesn’t explode near expiration [sorry for this one – it doesn’t match the pattern of the rest of the greeks ;)]
Vega is for how the option responds to changes in Volatility.
Theta is how the option changes in value as Time marches on.
There’s of course more to learn, just remember for now:
Best of luck. May the Greeks be with you.