First of all look carefully at this term. Then you will get a basic idea that what this name actually means. Blockchain means that the chain or block chains made of blocks. We all know what the chain is. By adding one to the same material as well as many other ones, it is called chain making it like a chain. So think about creating a chain of blocks by linking a number of blocks with one another, the blockchain is meant by the term. Well, blocks that are created by these blocks are basically stores information. Blockchain technology is already in use and in many cases it is also used. But the general interest of this technology was created in 2009, after the development of the cryptocurrency named bitcoin in 2009. Technically speaking, Blockchain is a distributed laser, which is open for everyone. When data is interconnected between blockbuster blocks, it is almost impossible to delete or cut any data in the data. but how?
Alright, to know it first, we need to know what each of these blocks has in blocks. Each single block in the complete blockchain consists of three things - the hash of the previous block in the data, hash and chain. In other words, each block in the blockchain has its own data, the block has its own hash and the hash block of the block that is just behind it. I understand the data, but what is the hash thing? Hash is basically an identifier. The hash of each block is its own and specific to everyone. In other words, the hash of two blocks can never be the same. This issue is very similar to fingerprints of people. Both people will never be the same as fingerprint, so the hash blocks of the two blocks will never match. And these hashes are generated according to the data stored in each block. Which means if a block data is changed, then the hash of the block will be changed. Now, think about why each block has the hash of its previous block. If every block has the hash attached to it before, no block data will be able to change it arbitrarily. So it is almost impossible to delete or change every data interconnected in Blockchain. Because, in this case, if you want to change the data in a block, then you have to change all previous block data with that block, otherwise the entire blockchain will be invalid or not and will not work. Hope you understand now!
Blockchain is a growing (database) record, called block, which is connected and secured using cryptographic techniques. Each block usually contains cryptographic hashes from the previous block, timestamp, and transaction data.
By design, blockchain is resistant to data modification. Blockchain is "a distributed ledger (open ledger) that can record transactions between two parties efficiently and in a way that can be verified and permanent.
To use it as a distributed ledger, blockchain is usually managed by a peer-to-peer network collectively by following certain protocols for communication between nodes and confirming new blocks. After recording, the data in the block cannot be changed retroactively without changes in the next blocks, which requires consensus of the majority of networks.
Blockchain was designed from the start to be secure by design and is an example of a high-level distributed computing system with Byzantine Fault Tolerance (BFT). Decentralized consensus can be achieved with blockchain. This makes blockchain suitable for recording events, medical records and other record management activities, such as identity management, transaction processing, documentation of evidence, food traceability, and voting.
Blockchain was created by Satoshi Nakamoto in 2008 and is used as a big book for public transactions of bitcoin cryptocurrency. Blockchain discovery for bitcoin makes it the first digital currency to overcome the problem of double spending without requiring a trusted authority or central server. This bitcoin design has also inspired other applications.