Entering the world of economic integration with the establishment of the World Trade Center in 1995, opened the way for international trade. When the trade happened big tycoons, business organizations, and institutions started to face problems in payment systems. These problems were due to the consequences of the flaws that were entangled with the central banks and banking sectors. To solve the equations of these flaws blockchain was introduced as the resolution.

Blockchain in. layman's terms are simply the immutable ledger that facilitates the recording and storing of information, this information is trackable. Information can be of anything whether it be some transactions, or assets ( tangible and non-tangible). The prominent characteristics of blockchain are decentralization.  Every business transaction is monitored or regulated by central agencies before the start, but with blockchains, there are monitored by a network of computers. Here, the central authority is bypassed.

Block

Information can be stored in anything on a piece of paper, or applications in books, and accounts. In blockchain technology, information is stored in a structure block.

Block: Block consists of three things:

1) Data 

Data is the collection of information about the sender, and the receiver address with the information in it.

2) Hash 

A Hash is a long string of words. This is the unique code taken as a fingerprint associated with the block. This helps to identify the particular block with others. 

3) The hash of the previous block 

As the block contains its hash and also contains the hash of the previous bloc. This is what links every block in a chain

HACKING 

When we use the word hacking it means tampering with the information inside the blocks. And also it means controlling overall the total computing power of blockchains.

If we try to tamper with the date of any block the hash changes. And also the hash of the previous hash, as blocks are chained to one another all the hash changes of chains which is not possible thus hacking of the blockchain can't be altered.

And the other point. What makes it secure is the decentralization attributes which means that the technology is linked to the network of computers. And every computer stores and records copies of the blocks. Those computers that are connected to this technology are called nodes. And these nodes are the miners.

The work of the miners is to check and verify the inputted data of the blocks. They will check whether someone has tried to tamper with it.

Anyone in this world can connect with the public ledger network and check and verify the data stored in the blocks. There is no need for a central authority to check, monitor, and regulate all these. These are what make blockchain decentralized.