The content of the blockchain is hosted on a server that resides in a data center on this beautiful planet. While browsing the web or using any applications, clients request content or data from application servers, commonly referred to as client-server architecture. However, today, clients can connect with peer clients as well and share data among each other. Such a massive collection of computers sharing data with each other is termed a P2P network. Blockchain is a P2P network of computers that computes transactions, validates them, and stores them in an ordered form in a shared ledger. This results in a distributed database that records all the data, transactions, and other relevant information. Each computer in a P2P network is called a node. Nodes are responsible for validating transactions, organizing them into blocks, broadcasting them to the blockchain network, and so on. Upon reaching consensus, nodes commit the block to the blockchain network and update their local ledger copy. This layer comprises of virtualization (creation of virtual resources such as storage, network, servers etc.). Significantly, nodes are the core of this layer. When a device gets connected to a blockchain network, it is termed and considered as a node. On a blockchain network, these nodes are decentralized and distributed.