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description: Introduction
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# Blockchain

Blockchain is a Distributed database that is continuously growing with list of ordered, immutable and time stamped records. A mathematical structure for storing data in a way that is nearly impossible to fake.

The following are the Blockchain main benefits

* Greater Transparency
* Enhanced Security
* Increased Efficiency and Speed
* Reduce Cost

#### **More in Detail...**

A **blockchain** is a decentralised, distributed and public digital ledger that is used to record transactions across many computers so that any involved record cannot be altered retroactively, without the alteration of all subsequent blocks (wiki)

A blockchain is a growing list of records called blocks. It is an open distributed database that can record transactions between two parties efficiently and in a verifiable and permanent way. Once a block is recorded in the chain, the data in any given block cannot be altered retroactively without alteration of all subsequent blocks, which requires consensus of the network majority. All the blocks in the chain are linked by the cryptographic hash of the previous block.

[Don & Alex Tapscott](https://blockgeeks.com/guides/what-is-blockchain-technology/) states that the blockchain is an incorruptible digital ledger of economic transactions that can be programmed to record not just financial transactions but virtually everything of value.

#### **History of Blockchain**

Before it was ever used in cryptocurrency, it had humble beginnings as a concept in computer science — particularly, in the domains of cryptography and data structures. The very primitive form of the blockchain was the hash tree, also known as a Merkle tree. This data structure was patented by Ralph Merkle in 1979, and functioned by verifying and handling data between computer systems. In a peer-to-peer network of computers, validating data was important to make sure nothing was altered or changed during transfer. It also helped to ensure that false data was not sent. In essence, it is used to maintain and prove the integrity of data being shared

![Source   https://en.wikipedia.org/wiki/Merkle\_tree](https://2817541381-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LMG0jZlhB-S0xohkYCn%2F-LTvcxDFiW-beU671K1V%2F-LTveq1cDeyVG2cuhMYG%2Fimage.png?alt=media\&token=6da8f584-712d-409e-87c5-afd9eb0a32fc)


In 1991, the Merkle tree was used to create a “secured chain of blocks” — a series of data records, each connected to the one before it. The newest record in this chain would contain the history of the entire chain. And thus, the blockchain was created.

In 2008, Satoshi Nakamato conceptualized the distributed blockchain. It would contain a secure history of data exchanges, utilize a peer-to-peer network to time stamp and verify each exchange, and could be managed autonomously without a central authority. This became the backbone of Bitcoin. And thus, the blockchain we know today was born, as well as the world of cryptocurrencies.


Merkle tree was first implemented in Bitcoin, but many other blockchains also implement Merkle tree structures similar to this or even more complex versions. In addition to blockchain Merkle tree structure is being applied in many other systems also.

Ethereum is one of the public blockchain which provides a platform for more complex applications. [It uses a complex version of Merkle tree called Merkle Patricia Tree which uses three separate Merkle trees](https://blockonomi.com/merkle-tree/).&#x20;

