Meet smart contracts
Begin with “Smart contracts, simply” and work toward “Smart contract knowledge check”. Each available lesson includes a visual explanation and a quick knowledge check.
Read in order or choose a topic below. Completion marks stay in this browser. All 20 lessons in this track are available.
- 01
Smart contracts, simply
Programs that apply rules on Ethereum.
5 MIN READ - 02
A counter as a contract
A small state variable and one rule make execution easier to picture.
3 MIN READ - 03
Functions and arguments explained
A function identifies an action; arguments supply the details.
3 MIN READ - 04
Reading a contract versus changing it
A local read can simulate execution; persistent updates need accepted transaction processing.
3 MIN READ - 05
What does contract state mean?
The values a contract currently remembers after accepted updates.
3 MIN READ - 06
Who can call a smart contract?
Reachability and permission are different questions.
3 MIN READ - 07
A contract has an address too
An address can identify code and its state, not only a key-controlled account.
3 MIN READ - 08
What is deployment?
Creation execution can install runtime code at a new contract address.
3 MIN READ - 09
What is contract bytecode?
Machine-readable instructions differ from human-readable Solidity.
3 MIN READ - 10
What is verified source code?
A source match helps inspection but does not certify safe behavior.
3 MIN READ - 11
What an ABI describes
The interface tells software how to format requests and results.
3 MIN READ - 12
What contracts cannot do alone
Deterministic execution needs explicit inputs and a trigger.
3 MIN READ - 13
What is an oracle?
A mechanism for supplying information a contract cannot directly observe.
3 MIN READ - 14
What is a permission check?
A rule determines whether the current caller may perform an action.
3 MIN READ - 15
What is an administrator key?
Some systems give an account special powers over configuration or upgrades.
3 MIN READ - 16
Can a contract be upgraded?
Some application designs can change behavior through explicit upgrade mechanisms.
3 MIN READ - 17
Why bugs can be expensive
Public execution can apply an unintended rule just as faithfully as an intended one.
3 MIN READ - 18
A vending machine analogy and its limits
An everyday comparison is useful only while its boundaries remain clear.
3 MIN READ - 19
Walk through a pretend contract call
Follow one input from the interface to its checked state update.
3 MIN READ - 20
Smart contract knowledge check
Connect interfaces, execution, persistent state and trust boundaries.
3 MIN READ