• Immature (piv) - The maturity of coins refers to their staking eligibility, which is controlled by their amount of confirmations.  Piv are considered mature once they have 101 confirmations, which takes about 101 minutes.
  • Immature (zPIV) - A new zPIV mint that has not yet been followed by 2 other mints of that denomination.  (Reduced from 3 to 2 on v3.0.5) (source)
  • Unconfirmed (piv) - A piv transaction that has not yet been included in a block
  • Unconfirmed (zPIV) - A new zPIV mint that has not seen 20 confirmations
  • Orphan block - A block that is no longer part of the active chain.  This can happen most often after fixing your chain or if you stake a block successfully, but someone else staked one slightly sooner.
  • Fork - In general terms, a fork is a divergence like a fork in a road.  The most common use of this term in cryptocurrency is for code or chain forks. In both situations, the data leading up to the fork will match, but after the fork it will differ between the forks.  
  • Chain fork - A divergence of a blockchain, usually due to expanding or constricting the rules about what kind of blocks are valid
  • Code fork - A copy of existing code to be developed toward different goals
  • Wrong chain - The incorrect blockchain, usually by not updating your software with a mandatory version in time
  • HD Wallet - Heirarchical Deterministic Wallet - A wallet that can use a seed mneumonic phrase to generate addresses and keys, rather than loading them from a wallet.dat file.  
  • SPV wallet - Simplfied Payment Verification - A wallet that relies on a full node elsewhere to send and recieve blockchain data.  The mobile PIVX wallets are examples of SPV wallets
  • GUI - Graphical User Interface
  • CLI - Command Line Interface
  • Zerocoin - A cryptographic blockchain privacy protocol that uses ZK Proofs to break linkage and hide balances.  https://pivx.org/zpiv/
  • Zerocash - Zerocash is a different method of using ZK proofs for privacy, used in ZCash.  
  • ZK Proofs - Zero Knowledge Proofs - Technology that allows you to prove you know a secret without disclosing the information.  Used in the zerocoin and zerocash protocols as part of the privacy mechanism
  • zk-SNARKS - Technology used in the zerocash protocol used by ZCash and soon to be adopted by Ethereum
  • zk-STARKS - A theoretical improvement to zerocash with no trusted setup, smaller proofs, and lower resource requirements
  • Scaled - A scaled transaction or balance indicates that it is on an old wallet version and the wallet has not been upgraded yet