Blockchains Introduction

What is a Blockchain? 

At its core, a blockchain is precisely what it sounds like—a sequence of blocks linked together. Each block chronicles the most recent, verified transactions or actions conducted by users within the blockchain network.

A Database

In its simplest use, a blockchain can be seen as a database. 

But databases have been around for ages! So does blockchain bring anything new?

Yes, because it is tamper proof database which can be decentralized, public, and trustless (it can operate without trusted third parties), and this is new.

Tamper Proof 

A blockchain's magic lies in its immutability. Once a block is added to the chain following validation, altering its content becomes impossible. This permanence is secured through sophisticated cryptographic techniques, with each block carrying the digital imprint of its predecessor, ensuring a verifiable and unbroken chain back to the very first block.

Decentralized 

Unlike conventional databases managed by a single entity, a blockchain's data is distributed across a global network of nodes. This architecture not only makes the system robust against censorship but also enhances its security. The more nodes participating, the more decentralized and secure the network becomes, making it exceedingly difficult for malicious actors to compromise the data integrity.

Public 

On most blockchains today, anyone can view the contents of a blockchain on any of the nodes (and/or download all its contents). All transactions and their histories are searchable (although there are some blockchains where this is not quite true, but this will be explained later 😉).

Trustless

Blockchain technology eliminates the need for intermediaries or trusted third parties. Anyone can join the network by setting up a node, contributing to the network's operations, and in return, potentially receiving a portion of the network's transaction fees as a reward.

A Distributed Operating System

When viewed through a more complex lens, a blockchain can be likened to a distributed operating system (OS).

What Exactly Is an OS?

Operating systems like Windows, MacOS, Android, and Ubuntu manage the hardware and software resources on a computer.

Blockchain as a Global OS

Imagine a blockchain as a globally accessible OS, running across countless servers worldwide. While the analogy isn't perfect and the specifics can vary significantly between different blockchains, the essence is that blockchains allow for the development and execution of decentralized applications (dApps) directly on the network. These dApps utilize blockchain data for input/output, enabling a wide range of functionalities, from financial transactions to automated agreements known as smart contracts.

Fun Fact

The first (albeit imperfect) instantiation of a blockchain dates back to 1995 and was published...in a newspaper!