Blockchain is a technology that can record information in such a way that it is nearly impossible to alter or hack. 

This data is stored across a network of computers, where each one has a copy of the historical records.

A blockchain can be compared to a public notebook, where anyone can add a new page with data, but once done, it cannot be erased or modified. 

To add new information, it has to be written on a new page of the notebook.

The idea of blockchains was first introduced by researchers Stuart Haber and W. Scott Stornetta in 1991.  
18 years later, it was implemented as a way to record financial transactions on the Bitcoin blockchain.

To grasp blockchains, let’s analyze the term:

• Blocks play the role of digital containers for different types of data. For example, blockchains in the financial sector would store transactional records.

• The chain refers to a sequence of blocks and ensures the right order. Once a block is added to the chain, it cannot be deleted.