A smart contract is a computer program or a transaction protocol respectively, which is intended to automatically execute, control or document respectively legally relevant events and actions according to the terms of a contract, of an agreement or of a negotiation.
With digital currency, there is a risk that the holder could make a copy of the digital token and send it to a merchant or another party while retaining the original.
An airdrop is a way to distribute coins. End users can generally get coins for free or in exchange for a small task, such as subscribing to a newsletter, sending a tweet or inviting other people via a personal affiliate link.
2 Factor Authentication is a double layer security measure. Most crypto exchanges use it. In order to log in, you not only need to enter a password, but also a code that you receive from the Google authenticator for example.
Bounties are simple tasks of jobs by the team behind a coin. These can be as simple as joining a Telegram channel or by (re)tweeting. It could also be a bit more difficult like a translation job for example. The participants receive rewards in the form of coins in exchange for completing these bounties.
Blockchain is most simply defined as a decentralized, distributed ledger technology that records the provenance of a digital asset.