Blockchain Concept
Blockchain is a decentralized distributed ledger, that allows data store in distributed nodes and no one has no owns and the controllability of that data. Simply it is kind of data source. But everyone in the network let access to the every data. Blockchain used for transfer the data without involvement of third party vendors, such as bank, government etc.
Blockchain consist of collection of blocks and which links together as a single linked list. A block basically contains any kind of data, hash of the data, previous hash, and timestamp.
Genesis block — A beginning block in the chain.
The blockchain generally starts from special type of block, which named as genesis block.
Let’s assume that someone change the block B data (see figure 2). The corresponding hash will change, but the block C’s previous hash is old, which also needs to be changed. So which invalidates the blockchain. So likewise all the blocks need to be changed. Therefore change of single block, quickly needs to be changed all the invalid blocks.
Since these days there available high speed computers, which generates thousands of hashes in a second. Therefore to avoid that issue, blockchain uses the concept of Proof of work. which used to slow down the creation of new blocks, because which is a computational problem, that takes some time to sort out. So this will archive the fraud prevention, increases the security and unchangeable reliable transactions.
