# 10 Terms You Can't Understand Blockchain Without

## 1. Block

A block is a digital storage unit containing a set of confirmed transactions, cryptographically linked to the previous block via a hash. In Islamic finance, each block represents a transparent, immutable contract, ensuring ownership rights and buyer protection without riba or gharar.

## 2. Chain

The chain is the sequence of blocks linked together in a tamper-proof manner. This secure linkage ensures every transaction is verifiable, aligning with Qist's principle of an open contract audited on BaseScan, where any party can review the contract history.

## 3. Smart Contract

A smart contract is a self-executing program that enforces the terms of an agreement. In Qist, the smart contract ensures the seller owns the asset, payments are in USDC, surplus is returned, and no riba or gharar exists. The contract is open and verifiable on BaseScan.

## 4. Hash

A hash is a unique digital fingerprint of data. It is used to link blocks and ensure data integrity. This guarantees transparency in decentralized Islamic finance, where transactions cannot be denied or tampered with.

## 5. How Qist Implements This

Qist builds on Base using smart contracts that implement Islamic finance principles: seller owns the asset, payment in USDC, no riba/gharar, surplus returned, 3-day grace period, open contract audited on BaseScan. Each transaction is stored in a block on the chain, ensuring transparency and trust.