What is a blockchain technology? How do they work as open source? What problems do they solve in the modern era?

What is Blockchain? 

Blockchain technology is being used to solve problems in many different industries, but what exactly is blockchain? How does it work, and how can you use it?

A blockchain is a sequence of blocks that contains information. The technique was originally described in 1991 by a group of researchers, who used it to timestamp digital documents so that their authenticity couldn't be questioned later on. However, it wasn't widely used until Satoshi Nakamoto adapted blockchain technology in 2009 to create the digital cryptocurrency Bitcoin.

How does work the blockchain? 

The idea behind blockchain is that data can be stored in a ledger that is shared among multiple parties. Because the system is decentralized and open, anyone can join it—and once data has been entered into this kind of blockchain, it becomes extremely difficult to change or delete. So how does this work? Let's take a closer look at what blocks are made up of each block contains some data, the hash of the block and the hash of the previous block.

Blockchains record transactions and other information to enable them to be identified later on. For example, blockchains keep track of the number of coins that have been used in each transaction and identify who sent money to whom by including a digital signature associated with each user's public key. You can think of a hash as being like a fingerprint. It identifies the contents of a block, and it's always unique—like no other has or will ever be made for that particular block.*

To create a block, you must first decide what information to include and then arrange it in the correct order. Once this is done, calculating its hash value (a long string of numbers) serves two purposes: First, if another person wanted to alter your data by adding or removing something—for example changing "Block 1" into "Block 2"—the new version would not have the same hash as before. Second, if we needed to check whether our block was altered without knowing exactly where on earth each item was located within it---like looking at an unknown book's title while purposely missing out one word from that sentence just so that we could later tell which letter had changed when running DNA sequence compare**Once the block is created and hashed,it can be safely stored away. Because the hash of each block is included in the next block, and because blocks cannot be altered once they've been added to the chain, blockchain technology offers a way for people who don't know or trust each other to build a dependable ledger together.

Let's take an example. Here we have a chain of three blocks: Block #1 points to block #2, which in turn points back to block #1—so each subsequent block refers back to its predecessor. This first "special" or genesis hash is what makes blockchain technology so powerful;

Because the Genesis block is uncorrupted and cannot be changed, it serves as a sort of checkpoint in the system. If you tamper with any subsequent blocks, those are corrupt because they no longer meet this initial standard

If Block 3 is modified, all blocks after it will no longer have a valid hash. As a result, tampering with one block will cause the rest of the chain to become invalidated. However, using hashes alone does not provide sufficient protection from malicious modification because computers these days are very fast and can calculate hundreds of thousands of hashes per second. You could effectively tamper with a block and recalculate all the hashes of other blocks to make your blockchain valid again.

What are the key components of the blockchain?

So to mitigate this, blockchains have something called proof of work. It's a mechanism that slows down the creation of new blocks. In Bitcoin's case, it takes about 10 minutes to calculate the required proof of work and add a new block to the chain.

 This mechanism makes it very hard to tamper with the blocks because if you tamper with one block, you'll need to recalculate the proof of work for all the following blocks. So the security of a blockchain comes from its creative use of hashing and the proof of work mechanism. But there is one more way that blockchains secure themselves, and that is by being distributed. Instead of using a central entity to manage the chain, blockchains use a peer-to-peer network and everyone is allowed to join. When someone joins this network, he gets a full copy of the blockchain. The node can use this to verify that everything is still in order. Now let's see what happens when someone creates a new block. That block is sent to everyone on the network. Each node then verifies the block to make sure that it hasn't been tampered with, and if everything checks out, each node adds this block to its own blockchain. All the nodes in this network create consensus. They agree about what blogs are valid and which aren't.

 Blocks that are tampered with will be rejected by other nodes in the network. So to successfully tamper with the blockchain, you'll need to tamper with all the blocks on the chain, redo the proof of work for each block, and take control of more than 50% of the peer-to-peer network. Only then will your tampered block become accepted by everyone else. So this is almost impossible to do. Blockchains are also constantly evolving. One of the most recent developments is the creation of smart contracts these contracts are simple programs that are stored on the blockchain and can be used to automatically exchange coins based on certain conditions.

Conclusion

The creation of blockchain technology picked up a lot of people's interest. Soon, others realized that this technology could be used for other things like storing medical records, creating a digital notary, or even collecting taxes. So now you know what a blockchain is, how it works on a basic level, and what problems it solves. And as well as thanks much for reading and visiting