Layer 1 vs Layer 2: How Ethereum and Rollups Relate
Ethereum Mainnet is layer 1. Learn how layer 2 handles transactions away from Mainnet, how rollups connect execution with data, and why network labels do not establish safety.
What Is a Blockchain Oracle? Understanding External Data Feeds
Blockchain oracles make offchain information available to smart contracts. Learn how to separate the feed’s role, its sources and trust model, and unanswered questions about availability and updates.
What Is ERC20? Understanding Ethereum’s Token Standard
ERC-20 gives token contracts a common interface. Learn how total supply differs from an address’s balance, what Transfer events specify, and why name, symbol and decimals are optional.
What Is a Smart Contract? Code, State, and Calls on Ethereum
Understand Ethereum smart contracts as code and state at an address, how user accounts invoke functions, and why offchain information requires a separate data source.
Ethereum Nodes and Clients: Roles, Types, and Verification
Understand how Ethereum nodes relate to execution and consensus clients, how full and archive roles differ, and what changes when data comes from remote RPC.
Ethereum Account Nonce: Understanding Transaction Sequence
Understand Ethereum’s account transaction nonce, its role in ordinary EOA sequencing, and why an RPC transaction count needs a specified block context.
How Is a Transaction Verified? Ethereum Explained
Ethereum transaction verification involves authorization, execution, block inclusion, and consensus. Learn why an included transaction can still have failed execution.
ERC-20 Decimals Explained: From Raw Units to Display
Understand ERC-20 decimals through raw integer units, a hypothetical scaling example and the distinction between optional EIP-20 metadata and OpenZeppelin’s default.
How to Read an Ethereum Transaction in a Block Explorer
Use the transaction hash to distinguish pending, failed and successful execution. Check the network, recipient and receipt before drawing conclusions.
Ethereum Gas Fees: Why the Fee Differs from the Amount Sent
Separate the amount you send from the cost of executing a transaction. A worked example explains gas used, gas price and failed transactions.