I'm new as well but the way I understand it is: an air drop is free coin given out by the developers of a coin as a mean of releasing it too as many people as possible before it goes on an exchange or is released to the general public through mining or other means. They do this to spread awareness of the coin and their concept. It varies from coin to coin. Someone else may have a better answer.
That's a pretty good explanation. In some cases established coins may do an airdrop as well (such as the recent Byteball and Stellar airdrops) as part of their publicity campaign.
It's a nice bonus when you can get free coins if you have the patiences to HODL them. Here's an example:
When NEM (New Economy Movement) launched in 2014 I signed up for an initial distribution and got 10,000 free NEM. Being the short-sighted bloke that I am, I noticed that it was already trading on Poloniex and that I could get a whole 50 cents for them! Whee! So I promptly sold them and patted myself on the back for the free pocket change. I mean, with a weird name like that how could it ever catch on?
Fast-forward to 2016 and one day I noticed that NEM had clawed its way onto the Top 100 chart at Coinmarketcap. Hmm. My 10,000 NEM were now worth $10. Did I dare buy back in and hope for further gains, or would I just wind up wiping out that 50 cent profit by losing a couple bucks if it deflated? After studying it a little more, I bought my 10,000 NEM back.
Then late this spring I sold them again for over $2,000. So I missed on the rise from 50 cents to $10, but thankfully I got to ride the rest of the wave. Let that be a lesson in HODLING!
Why did you only get 10 000 NEM? NEMstakes were free and held 2 000 000 NEM each.
