This is a long-awaited one for me. I personally have been trying to get into blockchain development for a while but always felt super intimidated and dropped it. Luckily, I chose to take it up as a subject in college and am super glad to link resources to developing the technology that helps decentralize the world.

Before we get into some technical details and the HOW of blockchain, we have to understand WHY blockchain in the first place. The WHY of blockchain makes it easier to get into the HOW of it.

There is a concept known as double-spending. In terms of money, it is spending the same amount of currency more than once. Double spending leads to creating fraudulent transactions, which obviously is not good for the economy or the individual. To prevent double spending, in the real world, we have banks that keep track of everyone’s funds and cross-check if everyone has a sufficient amount of money to be able to make a valid transaction.

But what about the digital world? For example, if digital money is a file, it can easily be copied and everyone can become a billionaire overnight. This is where blockchain comes in.

The goal of blockchain is mainly two-fold:

1. Prevent double spending in the digital world
2. Decentralization / Giving power back to the people.

So how does blockchain prevent double spending exactly? Well, let’s understand what’s happening when banks keep track of funds. Everyone has some amount of money which is recorded in a ledger / database, whenever a transaction occurs the bank is responsible for verifying that it’s a valid transaction or not, if it’s valid then allow the transaction to happen and update the ledger. Pretty simple, right?

We keep track of funds and verify transactions, that’s the core concept. Blockchain does this through something called a consensus mechanism. Put simply, every person has a copy of the ledger that keeps track of everyone’s funds. When a transaction happens, some people take up the responsibility to verify if the transaction is valid and tell everyone else, “Hey, this transaction is valid, here’s proof”. The other people check the proof and when there’s agreement among all or at least the majority of the people, you reach a consensus and the transaction is verified. Once the transaction is verified, everyone updates the ledger.

This might bring a lot of questions (and it should). How does this practically work? Why are there other people involved at all? Why can’t others manipulate their ledgers? How is this technically implemented? Won’t it be too slow?

and a whole lotta other questions. This blog is not gonna magically make you understand everything, it’s meant to give you a start. Blockchain is a get your hands dirty kinda thing to which there are resources at the very end.