Blockchain is a distributed data storage system, yet few know how it functions and where all the data is located.
Types of Nodes in Blockchain
There are several types of nodes, but the most common are full nodes and lightweight nodes. Full nodes store the entire history of the blockchain, validating all transactions and blocks since the beginning. These nodes play a crucial role in maintaining the integrity and security of the blockchain. Lightweight nodes, also known as SPV (Simple Payment Verification) nodes, store only partial data and rely on full nodes for confirmation.
Decentralized Nature of Data Storage
Unlike traditional databases, which are centralized and stored on specific servers, the decentralized nature of blockchain allows data to be copied and synchronized across thousands of nodes worldwide. This makes it extremely difficult to tamper with or lose data, as no single party controls the entire system.
On-chain and Off-chain Data Storage
In most blockchains, data is stored in structures called blocks. Each block contains a list of transactions and is cryptographically linked to the previous block, forming a chronological chain. Once a block is added, its data becomes permanent and immutable. However, not all data may be stored 'on-chain.' For large files or sensitive information, many blockchains use off-chain storage solutions, such as cloud servers or distributed systems like IPFS (InterPlanetary File System). In this case, the blockchain stores only a reference or hash of that information.
Thus, blockchain data is stored on a decentralized network of nodes, each of which either fully or partially holds the ledger. This distributed structure provides resilience, transparency, and security to the blockchain.
