Welcome to learning module 2, you will now be introduced to blockchain technology through a simple story. Imagine you want to sell your leather couch online. Maybe you post it on Facebook Marketplace or Craigslist. After you have found a potential buyer you would at some point need to involve your banks or a third party to complete the sale and receive the money. However, with the help of a blockchain network, the buyer could directly send the money to you. This is because the blockchain is decentralized, meaning no central authority like a bank will make the decision whether the money gets sent or not. Instead, the network will reach a consensus before adding another block to the chain network and processing the transaction. The consensus mechanism is similar to how you just reached a consensus with your keyword before you added learning block 1 to the board in front of you. These mechanisms ensure that everyone in the network agrees on the current state of the blockchain, kind of like an activity log in order to ensure that everything is in the correct order. Once the block is added to the network, it will have a time stamp and cannot be altered.