# blockchain

> distributed data store for digital transactions

**Wikidata**: [Q20514253](https://www.wikidata.org/wiki/Q20514253)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Blockchain)  
**Source**: https://4ort.xyz/entity/blockchain

## Summary

Blockchain is a concept [1][2][3].

## Summary  
Blockchain is a distributed data store designed for secure, transparent digital transactions. It organizes data into blocks that are cryptographically linked in a chain, ensuring integrity and immutability. This technology underpins systems like cryptocurrencies and supports decentralized applications across various industries.

## Key Facts  
- Blockchain is a type of **distributed ledger** and **database** system using cryptographic validation and consensus algorithms.  
- It was conceptualized and implemented by **Satoshi Nakamoto** in 2008 as part of the Bitcoin protocol.  
- Core components include **blocks**, **cryptographic hashes**, and **consensus mechanisms**.  
- Used in fields such as **cryptocurrency**, **non-fungible tokens (NFTs)**, supply chain tracking, and digital identity verification.  
- Classifications include **distributed data storage**, **computer network protocol**, and **data structure**.  
- Different from related concepts like **directed acyclic graph ledgers** and **federated ledgers**.  
- Maintained by multiple **WikiProjects** including WikiProject Cryptocurrency, WikiProject Computer Science, and others.  
- Aliases include **blockchains**, **block chain**, **ブロックチェーン**, **區塊鏈**, and **cadeia de blocos**.

## FAQs  

### Q: What is blockchain used for?  
A: Blockchain is primarily used for secure digital transactions, especially in cryptocurrencies like Bitcoin. It also supports NFTs, smart contracts, supply chain transparency, and decentralized finance (DeFi) platforms.

### Q: Who invented blockchain?  
A: Blockchain was invented by **Satoshi Nakamoto**, who introduced it in 2008 as the foundational technology for Bitcoin.

### Q: How does blockchain work?  
A: Blockchain works by grouping transaction data into **blocks**, which are cryptographically secured and linked in chronological order. Consensus mechanisms ensure all copies of the ledger remain synchronized and tamper-resistant.

## Why It Matters  
Blockchain represents a paradigm shift in how digital trust is established and maintained without requiring central authorities. By enabling decentralized, tamper-proof record-keeping, it solves long-standing issues around fraud, transparency, and control in digital transactions. Its applications span financial services, healthcare, logistics, governance, and more, making it a foundational technology of the digital age. As infrastructure for cryptocurrencies and smart contracts, blockchain enables new economic models and enhances data sovereignty for individuals and organizations alike.

## Notable For  
- First implemented as the core technology behind **Bitcoin** in 2008.  
- Enables **decentralization** and **trustless interactions** between parties.  
- Utilizes **cryptographic hashing** and **consensus protocols** to maintain data integrity.  
- Supports diverse use cases beyond currency, including **smart contracts** and **digital identities**.  
- Recognized globally with dedicated research institutions, such as the **Luxembourg Institute of Science and Technology** (established 2015).

## Body  

### Definition & Structure  
Blockchain is defined as a **distributed data store for digital transactions**. Transactions are grouped into **blocks**, each containing a cryptographic hash of the previous block, forming a **chain**. This structure ensures chronological ordering and makes alterations computationally impractical.

### Technical Components  
- **Blocks**: Units of data containing transaction information.  
- **Cryptographic Hash Function**: Ensures data integrity by linking each block securely to the next.  
- **Consensus Algorithm**: Mechanism used to agree on the validity of new blocks among distributed nodes (e.g., Proof of Work, Proof of Stake).  
- **Decentralization**: No single point of failure or control; copies of the ledger exist across multiple nodes.

### History & Development  
- Invented by **Satoshi Nakamoto** in 2008.  
- First implemented in **Bitcoin** in January 2009.  
- Since then, evolved into broader applications including Ethereum, Hyperledger, and private/permissioned chains.

### Applications  
- **Cryptocurrencies**: Bitcoin, Ethereum, Litecoin.  
- **Non-Fungible Tokens (NFTs)**: Digital ownership certificates.  
- **Supply Chain Management**: Transparent tracking of goods.  
- **Healthcare**: Secure patient records management.  
- **Government Services**: Voting systems, land registries.

### Classification & Relationships  
- Subclass of: **Distributed Ledger**, **Database**, **Computer Network Protocol**, **Data Structure**.  
- Instance of: **Concept**, **Academic Discipline**, **Field of Study**.  
- Related Fields: **Cryptography**, **Computer Security**, **Financial Technology**.  
- Different From: **Blockchain.com** (a company), Directed Acyclic Graph Ledgers, Federated Ledgers.

### Standards & Identifiers  
Various global databases and classification systems recognize blockchain:  
- **YSO ID**: 38227  
- **MeSH Descriptor ID**: D000081186  
- **Library of Congress Authority ID**: sh2016002790  
- **Bibliothèque nationale de France ID**: 17100738x  
- **STW Thesaurus for Economics ID**: 30190-0  

### Community Presence  
- Active communities on platforms like **Reddit** (/r/BlockChain), **GitHub**, **Stack Exchange**, and **Quora**.  
- Educational presence on sites like **Wikiversity**, **Vikidia**, and **Wikipedia** in over 60 languages.

## References

1. [Source](https://www4.hcdn.gob.ar/dependencias/dsecretaria/Periodo2021/PDF2021/TP2021/4610-D-2021.pdf)
2. [Jornada de Graduados del Instituto Universitario de la Policía Federal Argentina](https://iupfa.edu.ar/IUPFAnoticias/iupfanoticias005.html)
3. [INTRODUCCIÓN A LA TECNOLOGÍA BLOCKCHAIN: SU IMPACTO EN LAS CIENCIAS ECONÓMICAS](https://bdigital.uncuyo.edu.ar/objetos_digitales/15304/14.-introduccinalatecnologia.pdf)
4. [Source](https://github.com/JohnMarkOckerbloom/ftl/blob/master/data/wikimap)
5. [Nuovo soggettario](https://thes.bncf.firenze.sbn.it/termine.php?id=62079)
6. BBC Things
7. YSO-Wikidata mapping project
8. UMLS 2023
9. Quora
10. [Source](https://thenextweb.com/vocabulary/blockchain/)
11. National Library of Israel
12. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)
13. [Best Blockchain Posts - Reddit](https://www.reddit.com/t/blockchain/)