Transactions and Wallets

Question 1

Common transaction: inputs/outputs pattern?

Answer 1

1 input → 2 outputs (payment + change).

Question 2

Aggregating transaction: pattern & purpose?

Answer 2

Many inputs → 1 output; consolidate small UTXOs into one larger coin.

Question 3

Distributing transaction: pattern & purpose?

Answer 3

1 input → many outputs; split funds to multiple recipients.

Question 4

First check in Bitcoin txn validation?

Answer 4

Confirm each input references an unspent output (UTXO).

Question 5

Opcode sequence proving ownership in a P2PKH script?

Answer 5

OP_DUP OP_HASH160 OP_EQUALVERIFY OP_CHECKSIG.

Question 6

Fast mnemonic for validation pipeline steps?

Answer 6

“UTXO → Sig → Fee” (unspent, signed, fee-valid).

Question 7

Main downside of nondeterministic wallets (JBOK)?

Answer 7

Backup hassle; losing a key loses funds; can run out of fresh addresses.

Question 8

Main upside of hierarchical deterministic (HD) wallets?

Answer 8

Infinite addresses from one seed; single mnemonic backup; branch structuring.

Question 9

Why mnemonic seed words instead of raw hex?

Answer 9

12–24 words are human-readable and recreate the same root seed for recovery.

Question 10

Public vs private child key derivation?

Answer 10

Public: create receive-only addresses without spending keys; Private: needed to sign/spend coins.