An “airdrop” refers to a method of distributing digital assets to the public, usually to spread awareness of a new cryptocurrency. An airdrop is a marketing campaign for distributing free coins or tokens to new or existing holders of certain cryptocurrencies. Most airdrop campaigns require new users to do simple tasks like giving an email address, sharing news, referring friends or downloading an app in order to receive coins or tokens.
The effect of airdrop allows users to diversify their cryptocurrency holdings and gain profits if and when the asset rise in value. As for the network, airdrop spread awareness of the airdropped token, rewards early investors (through initial coin offering), and increase the holding of the blockchain network.
However, you should always be careful as there are cases where an airdrop acts like a scam to gain access to your data and private keys.