What is a Blockchain?

A blockchain is a type of digital ledger, similar to a database where information is stored electronically.

Traditional databases organize data into tables, whereas a blockchain structures data into "blocks" using advanced cryptography.

What sets blockchain technology apart from traditional databases is that it records and stores information in a way that is secure, transparent, and tamper-proof.

Decentralization in Blockchain

Unlike traditional centralized databases, where data is stored on a single server and can be modified, blockchain uses a decentralized system where copies of the data are distributed across multiple independent computers (nodes) worldwide. Each node validates the data within the digital ledger, creating a system that is highly resistant to hacking.

How Data is Recorded on a Blockchain

Once data has been entered on the digital ledger and validated, it will be ‘sealed’ and recorded into a block - at this point, it is virtually impossible to change or delete.

Each new block is timestamped and then linked with a reference to the block before it, creating a chronological, secure record and a continuous chain. Altering any information in the block would require changing all subsequent blocks.

Traditional databases can be vulnerable to mistakes or manipulation when shared by multiple users. Blockchain solves this by making sure every entry is independently verified and tracked. Any changes can only happen if the majority of participants in the network agree, ensuring the system stays secure and trustworthy.

---

Terms you should know:

Blocks 

Individual units of data that are securely sealed and linked together to form a continuous chain. 

Cryptography

The use of advanced mathematical techniques to secure data and prevent unauthorized access or changes.

Decentralized System 

A system where data is distributed across many computers (nodes) instead of being stored in one central place. 

Nodes 

Independent computers in a blockchain network that store, validate, and share copies of the data. 

Tamper-Proof 

Designed to prevent unauthorized changes or alterations to the stored data. 

Timestamped 

Each block is marked with the exact time it was created, ensuring a chronological record. 

Consensus

The process where most participants in the network agree on the validity of the data before it’s recorded. 

Validation 

The process of verifying and approving data to ensure its accuracy before it is added to the blockchain. 

Secure 

Protected against hacking, errors, or manipulation, making the data highly reliable.

---