How does Bitcoin and blockchain work? !

To begin, let's distinguish between the two concepts: blockchain (literally "blockchain") is a technology for storing information in a decentralized and secure way. Specifically, it is a database mathematically verified by each of the nodes that compose it.

Bitcoin is a use of this technology. It is a system allowing the nodes of a blockchain to exchange units of account in a secure and tamper-proof way.

It should be noted that the term "Bitcoin" with a capital letter denotes the decentralized payment system while the term "bitcoin" without the capital letter denotes the unit of account having the symbol "BTC". Thus, we say "I bought a bitcoin" and "Bitcoin is an original concept."

How does the blockchain work?
Contrary to what one might think, the principle is simple: imagine cubes placed next to each other and connected by a small rope. The leftmost cube is the "genesis block", the very first in the blockchain. It is connected to another block on its right by a mathematical equation whose solution is contained in this other block, this solution makes it possible to connect these two blocks to one another in a tamper-proof manner. In addition to this solution, the new block also contains a new mathematical problem whose solution found will create the next block.

When we say that we "mine" bitcoins, we are actually trying to solve the problem of generating a new block. Indeed, the creation of a new block generates new bitcoins which are given to the person (or rather the node) who discovered this block.

For this mode of operation to be valid, it is necessary that the answer is at the same time very difficult to find and easy to check. In this way, as soon as a node announces the resolution of a problem, the entire network will be able to quickly check it and validate the creation of a new block.

How does Bitcoin work?
Each new block created generates a number of bitcoins. Initially 50 bitcoins per block, this amount decreases regularly. Today, 12.5 bitcoins are created each time.

The transactions part is simple too: each bitcoin is attached to a pair of keys, one public and the other private. When the owner of a bitcoin decides to send it to someone else, he will broadcast information on the network saying that his bitcoin (whose property is proven mathematically) must now be considered as attached to another address . The network will verify that the given order emanates from the true owner of this bitcoin and will register this transaction in the last known block. Once confirmed by several nodes, the transaction is irreversible.

By constantly checking all the nodes of the network, each bitcoin is transferred from one address to another in complete security since the trusted third party is no longer a single entity (as in the case of a card transaction). bank, where the trusted third party is your bank), but by thousands, even tens or hundreds of thousands, who check each transaction using a unique algorithm specific to the source code of the blockchain.