Welcome to Steve’s guide to Blockchain and Crypto where you can learn the basics of blockchain and crypto technologies.

I started learning about blockchains and crypto currencies several years ago and found that there were very few websites focused on the technologies and and the basics as most were geared more to investing.

I started this site to help me learn more about blockchain and crypto currency technology and I hope you will find it useful as part of your learning process

To start we need to understand ..

What is Blockchain?

There are several definitions on Blockchain.

IBM definition –Blockchain is a shared, immutable (permanent and unalterable) ledger that facilitates the process of recording transactions and tracking assets.

Many definitions include the word shared but a Blockchain ledger doesn’t need to be shared, but often is. So I prefer

It is an immutable (cannot be changed) ledger for recording transactions.

Although it doesn’t need to be shared the sharing makes it almost impossible to change as you would need to change each version of the ledger.

See How Blockchain Works for more details

Blockchain vs Database

A database organises data using table whereas a Blockchain puts data into blocks.

Each block in a Blockchain is linked to the previous block to form a chain hence the term Blockchain.

Changing any data in any of the blocks will make the chain invalid which is why a Blockchain is immutable.

With a database data can be changed in any table without it affecting any of the other tables.

Blockchain Uses

What information can be stored on a Blockchain?

Almost any type of information can be stored on a Blockchain including applications (smart contracts,games).

Although currently the main use for blockchain is for crypto currencies, the use cases are expected to grow into the real estate, health care, stock trading, voting etc. You can find lists of example uses here and here.

Blockchain and Crypto

The most common use of blockchain is for crypto currencies which has been made famous by Bitcoin.

There are many different types of crypto currencies just like there are many different national currencies ($,£, Yen, Euro etc).

Some of these cryptos use the same basic blockchain and others use totally different ones.

Blockchain and Encryption Technology

Blockchains use encryption but most blockchains aren’t encrypted. The Bitcoin blockchain isn’t encrypted and the transactions stored on the blockchain can be read by anyone.

Encryption technologies are used for crypto accounts and for linking the blockchain so that blocks cannot be chanined.

Blockchain and Storage

Because a blockchain is a linked chain of transactions the blockchain grows with each new transaction and so can grow very large.

The Bitcoin blockchain is currently over 300GBytes in size. However there are techniques like pruning that allow you to reduce the size.


Are There Different Blockchains?

Just as there are many different databases there are many different Blockchains currently in use.

The Blockchain used by Bitcoin is different from the one used by Ethereum etc.

You will also see the terms layer 1 and layer2 blockchains being used see –Examining Blockchain Layers



Bitcoin is the crypto currency that made blockchain technology mainstream.

All crypto currencies that have followed have lent heavily on the Bitcoin blockchain technology.

Because of this learning how Bitcoin works and the technolgy behind it is a very good way of learning about blockchains in general.