Ethereum doesn’t greet you with a “Sign up with email” screen. To use it, you go through wallets, and every action you take costs a small fee called gas. Day 7 is about understanding both in human language, not protocol diagrams.
What is an Ethereum wallet?
An Ethereum wallet is an app, browser extension, or hardware device that lets you create accounts, hold assets like ETH and tokens, and interact with dApps. Under the hood, it manages your cryptographic keys and signs transactions on your behalf.
Two core ideas sit behind that UI:
- A public address – something you can safely share so people or apps can send you assets (like an account number).
- A private key or seed phrase – a secret that controls the account; anyone who has it can move everything in that wallet.
Non‑custodial wallets (MetaMask, many mobile wallets) give you direct control of keys; custodial wallets (some exchanges) hold keys for you and show you balances in an account view.
What does a wallet actually do?
When you “use Ethereum”, the wallet is doing more than just displaying numbers. It:
- Shows you what a transaction or contract call is about to do: send ETH, approve a token spend, mint an NFT, stake in a protocol, etc.
- Asks you to confirm or reject that action.
- Signs the transaction with your private key and broadcasts it to the network so validators can include it in a block.
So each wallet popup is effectively asking: “Do you really want this change recorded on‑chain, at this cost?”
What is gas on Ethereum?
On Ethereum, gas is the fee you pay to get the network to process your transaction or smart‑contract interaction. Validators use computing power and storage to execute your transaction; gas fees compensate them and prevent spam.
Every on‑chain action has:
- A certain amount of work required (measured in gas units).
- A price per unit of gas (in gwei, a tiny fraction of ETH) that changes depending on how busy the network is.
Your total fee is roughly:
gas used × gas price, paid in ETH.
Why do gas fees spike?
Ethereum has limited transaction capacity per block, so when lots of people want to transact at once, they bid up gas prices for faster inclusion. It’s a bit like surge pricing for block space.
In practice, that means:
- Simple transfers (sending ETH from you to a friend) usually consume less gas than complex DeFi or NFT interactions that touch multiple contracts.
- Time of day and network conditions matter; wallets and explorers often show estimated fees or let you choose between “slow / medium / fast” options with different prices.
As a user, you don’t set gas mechanics from scratch—you mostly choose how much you’re willing to pay for speed.
How wallets and gas feel in a real dApp session
A typical dApp interaction looks like:
- Connect wallet – you give the site permission to see your public address and suggest transactions; this step usually doesn’t cost gas.
- Approve a token – you authorize a smart contract to spend a specific token on your behalf (for example, so a DEX can swap it). This is an on‑chain transaction and costs gas.
- Do the main action – swap, lend, stake, mint, etc. Each of these is another transaction with its own gas fee.
To a newcomer, that’s the confusing bit: clicking a single button in a dApp might correspond to one or more real blockchain transactions, each with a visible cost in ETH.
Top comments (0)