Collateral: In the context of cryptocurrency, "collateral" refers to assets that a user locks up or pledges as security when participating in certain blockchain-based systems or financial services. Collateral is often required to mitigate risks and ensure that participants have a stake in the network or service. 

Consensus: The process by which nodes in a blockchain network agree on the validity of transactions and reach an agreement on the state of the blockchain. Common consensus mechanisms include Proof of Work (PoW) and Proof of Stake (PoS).

Cryptography: The practice and study of techniques for securing communication and data from adversaries. In the context of cryptocurrencies, cryptography is used to secure transactions and control the creation of new units.

Cold Wallet: A cryptocurrency wallet that is not connected to the internet, providing an added layer of security by protecting the private keys from online hacking attempts. Cold wallets are often used for long-term storage of cryptocurrencies.