This isn't an airdrop, it's a fork.
Its an intentional fork away from Bitcoin to create a new crypto currency called BitcoinCash (BCC), all the coins and their addresses are effectively in both chains at the time of the fork.
If you have the private keys to those addresses, you will own the coins in both forks.
So if you have 2 BTC in your own wallet before the fork, after the fork you will have 2BTC and 2BCC. You can spend on either chain, but unless something is put in place to prevent a replay attack, transactions from one chain can simply be copied by anyone to the other chain, and the transactions will then be mirrored there.
It is very likely that the value of your 2BTC + 2BCC after the fork will be less than the value of 2BTC before the fork.
So exciting how things will turn out come this Aug 1.
Everyone in crypto is watching, speculating, betting, not sleeping, etc...
So better secure your
BTC first, and then, treat as bonus if you are getting this bitcoincash.