Quick overview
This glossary explains core MetaMask terms and Web3 concepts you’ll see while using a software wallet for DeFi, NFTs, staking, and dApps. I’ve been using browser and mobile setups daily for months, and what I’ve found is that clear definitions save time and reduce risk. Short definitions first, then practical context and links to deeper guides.
Seed phrase & private keys
Seed phrase — A list of words (usually 12 or 24) that reconstructs your wallet. Treat it like the master key to every account derived from that wallet. Write it down on paper. Store it offline. Write it down on paper.
Private keys — The actual cryptographic keys for a single address. Exporting a private key gives direct access to that one account. Private keys should never be entered on unknown sites.
Why the difference matters: your seed phrase can regenerate multiple private keys. Lose the seed phrase and you lose all accounts tied to it. I once copied a seed phrase to cloud storage (bad idea) and had to move funds after feeling uneasy. Learn secure backup options in backup-recovery-seed and backup-recovery.
Accounts, import/export, and recovery
Account vs address: an account is the wallet identity within the software wallet; an address is the on-chain destination you share. You can create additional accounts within the same seed phrase or import separate accounts using a private key. See step-by-step import at import-private-key and account management at manage-accounts.
Restore and sync: restoring from your seed phrase re-creates accounts (if they were derived in the same path). If a token doesn’t show up, add the custom token or switch networks. For restore instructions see create-restore-wallet and restore-seed-sync.
RPC, networks, and EVM-compatible chains
RPC (Remote Procedure Call) lets your wallet talk to blockchain nodes. When you add a custom node URL (a custom RPC), you tell MetaMask which node to query for balances, transactions, and gas estimation. That’s an "RPC MetaMask" setting (you’ll find it under network settings). A misconfigured RPC can show incorrect balances or fail to broadcast transactions.
EVM-compatible MetaMask means MetaMask supports chains built on the Ethereum Virtual Machine (EVM), like Polygon or BSC, though you may need to add them manually. For adding networks see add-custom-network and chain-specific guides such as add-polygon, add-arbitrum, and add-optimism.
Layer 2 MetaMask: Layer 2 networks reduce gas fees and improve speed. You still manage funds in MetaMask, but gas-fees and transaction flow differ (see gas-fees-l2 and layer2-networks).
Connecting to dApps & WalletConnect
dApp provider injection — When a browser extension injects an Ethereum provider object into pages, dApps detect it and can prompt connection requests. That’s how many web dApps ask for wallet access.
WalletConnect — A protocol (and QR/URI flow) that links mobile wallets to web dApps without relying on browser injection. Use WalletConnect for mobile linking (see walletconnect-mobile-linking and connect-walletconnect). Which should you use? If you’re on mobile and prefer not to use an in-app browser, WalletConnect is handy. But remember session approvals still grant dApps permission to view accounts.
See step-by-step connection tips at connect-dapps and connect-to-networks.
Token allowances, swaps, and gas fees
Token allowance (token approval) — When an ERC-20 approval grants a smart contract permission to move tokens from your address. Unlimited approvals are convenient but risky. I once approved an unlimited allowance to test a protocol and later revoked it after reviewing contract activity. You can revoke approvals (and you should review them) via token-approvals-revoke and revoke-approvals.
Built-in swap — Many wallets include swap aggregators that route trades across DEXs for better prices. Check slippage, routing, and fees before confirming. For in-wallet swap guidance see swaps-in-wallet and in-wallet-swap.
Gas fees MetaMask — MetaMask shows gas suggestions; on EIP-1559 chains you’ll see base fee and priority fee options. Gas estimation can be conservative. See gas-fees-eip1559 and gas-fees-and-l2 for optimization tips.
Security: non-custodial, hardware, and best practices
Non-custodial MetaMask means you control private keys and seed phrases; MetaMask does not custody funds. That gives you full control and full responsibility. Keep backups offline. Use hardware wallets for larger balances; hardware devices add a layer of protection (see hardware-wallets-overview and connect-ledger).
Phishing and approvals: watch URLs, avoid unknown dApps, and confirm transaction details. Transaction simulation and phishing detection features help, but they aren’t foolproof. If you suspect a token or dApp is malicious, revoke approvals immediately and move assets if needed.
For backup choices and lost phone recovery see backup-recovery and lost-phone-recovery.
Staking, NFTs, bridges, and account abstraction
Staking via MetaMask is often a gateway (you connect to a staking interface or contract). Wallets may support liquid staking flows but validator selection and slashing policies depend on the protocol. See staking-via-metamask and staking-guide.
NFT support — MetaMask can display collections and send NFTs. Hide spam collections and confirm contract addresses before accepting NFTs (see nft-management).
Cross-chain bridges — Built-in bridging options exist, but bridges carry their own risk profile. Use audited bridges and double-check token/wrapper details at cross-chain-bridges and bridges-crosschain.
Account abstraction & smart contract wallets — Smart contract wallets enable session keys, batched transactions, and gasless UX. They change the trust model (some logic lives on-chain). Learn more at smart-contract-wallets-aa.
How-to: common tasks (step by step)
How to revoke an approval (quick):
- Open your wallet and navigate to approvals (see token-approvals-revoke).
- Select the token and contract.
- Choose revoke (or set allowance to zero).
- Confirm the transaction.
How to add a custom RPC (quick):
- Open network settings.
- Click Add Network and enter RPC URL, chain ID, currency symbol.
- Save and switch networks.
See add-custom-network and connect-to-networks for details.
How to connect WalletConnect (mobile): follow walletconnect-mobile-linking and connect-walletconnect.
Mobile vs extension vs desktop — quick comparison
| Feature |
Browser extension |
Mobile app |
Desktop / DApp integrations |
| dApp provider injection |
Yes (injected) |
Limited (in-app browser) |
Depends on integration |
| WalletConnect support |
Yes |
Yes (often primary) |
Yes |
| Network switching |
Fast |
Good (tap) |
Varies |
| Best for |
Desktop DeFi sessions |
On-the-go transactions |
Development and integrations |
| Security trade-off |
Convenient, lower than hardware |
Most convenient, higher exposure |
Depends on setup |
And remember: the convenience-security trade-off is real. But with careful habits, hot wallets are practical for daily DeFi.
FAQ
Q: Is it safe to keep crypto in a hot wallet?
A: Hot wallets are designed for everyday use. They’re non-custodial, which gives you control. For larger holdings consider hardware wallets; see hardware-wallets-overview.
Q: How do I revoke token approvals?
A: Use the approvals UI or a revocation tool and confirm the on-chain transaction. See token-approvals-revoke.
Q: What happens if I lose my phone?
A: If you have your seed phrase backed up, restore on another device. If not, funds are at risk. See lost-phone-recovery and backup-recovery.
Conclusion & next steps
Glossaries are most useful when paired with action. If you want to set up MetaMask on desktop, see install-metamask-extension. For mobile setup, follow install-metamask-mobile-app. To create or restore a wallet, visit create-restore-wallet and secure your seed phrase using backup-recovery-seed.
If you prefer hands-on walkthroughs, try the step-by-step guides linked above. I believe learning by doing, with small amounts first, reduces mistakes and builds confidence. Ready to try a safe test transaction?
