Blockchain is most simply defined as a decentralized, distributed ledger technology that records the provenance of a digital asset.
An altcoin is any cryptocurrency or token created after the Bitcoin was developed.
DAO is an abbreviation of ‘Decentralised Autonomous Organization’. This is basically an organisation that runs automatically on itself without any human interventions. The work is automatically excecuted through Smart contracts.
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.
Bitcoin is a digital or virtual cryptocurrency created in 2009 that uses peer-to-peer technology to facilitate instant payments.
A ‘51% attack’ refers to a possible attack on a blockchain by a group of ‘miners’, who hold more than 50% of the hashrate. In such a situation the ‘miners’ have the possibility to deliberately not confirm transactions or to issue transactions twice (double-spend).