Similar concepts, different jobs

Blockchain comparisons

Compact references for the distinctions learners often blur while moving from intuition to implementation.

Proof of Work vs Proof of Stake

Two ways to make Sybil attacks expensive: burn external energy or put internal capital at risk.

A public key verifies signatures; an address is a shorter receiving identifier derived from key material.

A database optimizes trusted coordination; a blockchain accepts overhead to coordinate without one operator.

Hashing proves integrity without recovery; encryption hides data so an authorized party can recover it.