🌐What is Blockchain

Blockchain is usually referred to as 'distributed ledger technology' (DLT). It was known in 2008 thanks to Bitcoin, the first cryptocurrency to exploit this technology, however the origins of this mechanism date back much earlier: when in 1991 researchers Haber and Stornetta introduced a computationally practical solution to mark digital documents so that they do not could be backdated or tampered with.

The blockchain is a structured database in the form of a chain of blocks, each of which contains a series of information. The blockchain is ideal for data transmission because it provides immediate, shared and completely transparent information that is stored in an immutable ledger.

In blockchain databases, information cannot be changed once the containing block is added to the chain. It is the use of hashes and time stamps that make the chain extremely secure.

In addition to possessing the inherent security features of a blockchain database, the decentralized blockchain makes use of a peer-to-peer network. Members of this type of network do not need to know or trust each other and each of them gets a copy of the same blockchain ledger. In this sense, there is no main copy (a "master" copy) stored in a centralized place and the task of continuously validating the accuracy of the blockchain is entrusted to the huge amount of copies generated. This decentralization eliminates the need to trust a central authority and at the same time protects the blockchain from hacking attempts. If a hacker tried to alter the blockchain, in fact, he would only modify his own copy. This new altered copy would not match the copies stored on the other computers on the network, and therefore would not be validated.