Here are some essential concepts to understand in the world of cryptocurrency:

1. 1. Blockchain: A distributed, decentralized ledger technology that records transactions in a secure and transparent manner.

2. Cryptography: The art of secure communication in the presence of third parties.

 3. Cryptocurrency: Digital or virtual currency that uses cryptography for security and operates independently of a central bank.

4. Wallet: A digital wallet is used to store and manage cryptocurrency. It contains the user's public and private keys, and allows them to send and receive funds.

5. Public key: A unique address that is used to receive cryptocurrency transactions.

6. Private key: A secret key that is used to authorize cryptocurrency transactions.

7. Mining: The process of verifying and adding transactions to the blockchain by solving complex mathematical problems.

8. Hash function: A mathematical function that takes an input (such as data or a file) and produces an output of fixed length, used for creating digital signatures and ensuring data integrity. 

9. Proof of work: A consensus mechanism used by some cryptocurrencies, where miners must solve mathematical problems to validate transactions and receive rewards.

10. Altcoins: Alternative cryptocurrencies to Bitcoin, such as Ethereum, Litecoin, and Ripple.