Isolated and cross margin are two different collateral allocation strategies for leveraged positions. The distinction determines how much of your account is at risk per trade — not how much leverage you can take.

Spot and futures are fundamentally different contracts. Spot = ownership at current price. Futures = leveraged price exposure via contract. This explains the mechanism behind both — including how perpetual funding rates work and what open interest actually signals.

Order books form prices through posted bids and asks. AMMs use a formula applied to pool reserves. The difference determines how costs hide, who bears risk, and what breaks under stress.

A soft fork tightens rules without breaking old nodes. A hard fork changes rules in a way old nodes reject. The difference determines whether a protocol upgrade creates one chain or two.

Order books and AMMs are two different mechanisms for price discovery and liquidity provision. The distinction explains slippage curves, impermanent loss, and why each model dominates different markets.

Soft forks and hard forks are both protocol upgrades — but the difference determines whether old nodes accept the change or split from the network. The mechanism is a single technical criterion: backward compatibility.

On-chain transactions are recorded and enforced by the blockchain's own consensus. Off-chain transactions aren't — and that difference determines who you're actually trusting. The gap between Lightning channels, rollups, and custodial ledgers is larger than the label suggests.

Permissioned and permissionless describe who can validate — not who can read. The distinction determines consensus algorithm, trust model, and attack surface. Here's how the mechanism actually works.

Public blockchains are permissionless — anyone can join, validate, and audit. Private blockchains restrict access to approved participants. The real difference is where trust lives and what "verifiable" actually means.

Permissioned and permissionless describe who can participate in consensus — not data visibility. The two axes are independent, and conflating them obscures the real architectural trade-offs.

The distinction between public and private blockchains isn't philosophical — it's architectural. Each design embeds a different trust assumption, and that assumption determines everything: who can validate, what the failure modes are, and whether the ledger is actually trust-minimized or just distributed record-keeping.

ERC-721 and ERC-1155 are both NFT standards, but they solve different problems. ERC-721 handles unique tokens one at a time. ERC-1155 handles multiple token types — fungible and non-fungible — in a single contract with batch operations.