As the name suggests, it’s a chain of block. And here the blocks are unique from each other. In terms of Computer Science, it’s basically one data-structure. The type of this data-structure is linked list. So each blocks points to it’s previous block.
As shown in the above figures, it mainly contains the transactions. Transactions mainly contains three information. The information of senders, the information of receivers and the information about the contents that we are sharing.
Now what differs block-chain from other technology is it’s decentralization property. The addition and removal of these blocks are done in a decentralized manner. There is no single authority present for addition and removal of these blocks.
One of the most popular platform for storing such blocks is Etherum. These blocks from the Etherium can be added, removed or altered by using ‘Smart Contracts’. This block-chain technology is in it’s early phases. It will gain more popularity if the reading of blocks and addition of blocks becomes cheaper.