How to Explain Blockchain to your Grandma
Tags: blockchain, beginners
Published: 2022-05-29 03:56:28

#Intro:

I plan to write a few posts that will serve as personal summaries of topics related to web3 that I find complicated.  I framed this one as a letter to my very non-tech savvy grandma explaining the concept of blockchain by analogy.  

*Please* let me know how I can improve.  

Dear Grandma,

I’ve never sent a letter before, so you’ll have to call me to scold me on my poor manners later. In the meantime, I wanted to tell you what I know about this cool idea called a Blockchain. First, I’ll explain what that word means, then I’ll talk about why it can be useful sometimes, and I’ll finish by talking about some different blockchain designs.

## What is a blockchain?

A blockchain is a computer program that serves as a list of previous events.  You can follow each event (or block) on the chain all the way to the beginning, kind of like a family tree.

Kind of like a family tree. It can be edited as you go, but everyone needs to have the same version of events.

Each event is “written down” on a “block”, and each block connects to the one before it to form a “chain” of blocks. (That’s why it’s called a Block Chain). The first thing a blockchain was used for was money, so it’s natural to think of most events as “transactions''.

## Why use a blockchain?:

No third party middle-man needed: Do you remember having to pay the bank $25 just to send Uncle Kevin some birthday money?

Trustless peer to peer: Or wanting to buy a necklace from an ad you saw on TV but refusing to call the company because you would have to give them your credit card information

A blockchain is a tool that people can use to solve these problems.

It does that the same way people solve the problem of reneging during spades— everyone keeps track of every transaction that happens. But instead of mentally keeping track of everything, people log every transaction using their computers. If anyone spots a transaction that didn’t happen (like my mom playing a spade two turns after she claimed she had run out), that list of events is deleted and replaced with the one that everyone else agrees on.

## Different types?

Blockchains were invented for people to copy the idea and put their own spins on it. Less like the Mona Lisa, more like your fried chicken recipe. So there are several different designs of blockchains that are built for different purposes.  Bitcoin's blockchain is used to store people's wallet information (almost like a bank), while Ethereum's blockchain can do a few more things than that.

## Okay, but what’s a Bitcoin?

Today there are many different groups using different blockchains for their own projects. Some people are using them to store artwork transactions, some healthcare companies are using them, and of course, some people are designing money that stores its transactions on them. This money is called a “cryptocurrency”.

One you might have already heard of is Bitcoin, but there are plenty of others like Ethereum, Solana, etc.  These each deserve their own articles, so I will write more about them in the future.

Thanks for sticking with me through all of that, grandma! Let me know if any of that made sense and how I can explain better next time. Write back when you get the chance!

With much love from your favorite grandson,

Ryan

*Please let me know if anything I said here is inaccurate or if you have any feedback that could help me improve my writing in general.*

(Better) Sources (of Information):

[3Blue1Brown Video Explanation](https://www.youtube.com/watch?v=bBC-nXj3Ng4)

[Original Bitcoin Whitepaper](https://bitcoin.org/bitcoin.pdf)