Blockchain is a register that allows information to be stored and exchanged in a secure, reliable and non-modifiable way, such as a cadastre or a notarial register.
In short, it is a database. To this, it should be noted that this database is distributed, it is shared by all of its users.
It must therefore be understood that there is no central mechanism for managing the Blockchain, it is a completely autonomous system.
The decentralized nature of the Blockchain, coupled with its security and transparency, promises much broader applications than the monetary field.
How to talk about Blockchain without tackling the concept of token.
A token is a digital asset issued and exchangeable on a Blockchain. This asset has the following characteristics: tamper-proof, recording of exchanges in an immutable register, security of exchanges, etc.
It is customizable, so that it can, for example, be used in a decentralized application, commonly known as Smart Contract. As such, it can represent a right to use a Blockchain product or service; voting rights; copyright; a way topay ; a reputation ; etc.
We can classify the use of Blockchain in three categories:
Applications for asset transfer (monetary use, but not only: securities, votes, stocks, bonds, etc.).
Blockchain applications as a registry: it thus ensures better traceability of products and assets.
Smart Contracts: these are stand-alone programs that automatically execute the conditions and terms of a contract, without requiring human intervention once started.
The fields of exploitation are immense: banks, insurance, health and industry, supply chain of many sectors, voting …
Public: it allows all its users to participate in the validation of transactions and a reading of the register to all persons without restriction. Editing transactions is almost impossible.
Private: the manager chooses the users and validates the blocks. Reading transactions in a private Blockchain is often only open to users. It is also generally possible to arrange a modification of transactions by the manager.
Hybrid: this is a Blockchain model where only the limited and selected nodes can be users, verify and approve transactions. A modification of the register would be possible by most of the nodes. Reading is in principle private between users