A brief blockchain breeze throug Blockchain: an unalterable record of transactions that is public and distributed across a peer-to-peer network. Facilitates decentralization, transparency, and traceability of transactions .Cryptocurrency: digital currency that IS NOT issued by a central entity ECDSA (Elliptic Curve Digital Signature Algorithm): a cryptographic algorithm used in Bitcoin to sign transactions. It is a one-way formula, where a user’s public key can be generated from their private key. But, with an individual’s public key, a fraudulent person can’t compute that individual’s private key.P2PKH (Pay to PubKey Hash): when transactions are made, the cryptocurrency is directed to the hash of the receiver’s public key rather than just their public key as it is in P2PK (Pay to PubKey). This adds more security and privacy to transactions Runtime in Big O Notation: runtime refers to how long a function takes to execute especially as we scale the input size. E.g. O(n^2) < O(2^n)NP (Nondeterministic Polynomial Runtime): NP problems are problems that can be solved in polynomial runtime. In Big O notation, that refers to n to any power.