Foundations of money and computation
Build the mental models needed before touching a transaction.
Follow these 7 lessons in order, or choose the topic you need. Each lesson combines an explanation, a worked example and practice inside the Guild.
What money does
Money helps people compare value, exchange goods, settle debts, and carry purchasing power across time. Different forms of money make different trade-offs.
35 minutes · Open lessonLedgers and double spending
A ledger records who can spend each scarce digital unit. A shared order prevents two conflicting payments from both becoming final.
45 minutes · Open lessonBits, bytes, hex, and endianness
Computers store Bitcoin data as bits grouped into bytes. Hexadecimal is a compact way to display those bytes, while byte order determines how a number is read.
55 minutes · Open lessonData structures and state machines
Bitcoin tracks spendable transaction outputs instead of account balances. Every valid transaction consumes existing outputs and creates new ones.
65 minutes · Open lessonNetworks and adversaries
Bitcoin nodes exchange information over an imperfect network. They must remain safe when messages arrive late, connections split, or peers lie.
35 minutes · Open lessonOpen-source verification
Anyone can inspect the rules, run the software, and reproduce a result. Security comes from independent checks rather than trust in one operator.
45 minutes · Open lessonCompactSize and Bitcoin byte fields
Parse variable-length counts, fixed-width integers, hashes, scripts, and length-prefixed vectors without confusing display order with serialized order.
55 minutes · Open lesson