What is cryptocurrency and blockchain? How does it really work?

Let’s be honest — if you’ve ever tried to understand cryptocurrency and came away more confused than when you started, you’re not alone.

At Fitted Tech, we work with clients across industries, and even seasoned engineers will admit: “I get the buzzwords… but what is crypto actually doing under the hood?”

Let’s break it down like developers — no hype, no fluff.

🔍 It All Starts with the Problem

Imagine trying to keep a shared Google Sheet of financial transactions with strangers on the internet.

• You don’t trust them.
• They don’t trust you.
• But somehow, you all need to agree on who paid who, when, and how much — and no one should be able to change the past.

That’s the core problem cryptocurrency solves:

How do you build a shared source of truth without a central authority?

🧱 The Blockchain: A Fancy Name for a Tamper-Proof Log

At its core, a blockchain is just an append-only ledger — like a growing array of JSON objects.

Each block looks something like this:

{
"previousHash": "abc123",
"transactions": [ { "from": "Alice", "to": "Bob", "amount": 10 } ],
"nonce": 928174,
"hash": "0000abcdef..."
}

Each block contains:

• A bunch of transactions
• A reference to the previous block’s hash
• A nonce — more on that in a second
• And a new hash for the block itself, based on everything inside it

Once a block is accepted, it’s locked in forever. Change anything, and the hash breaks. The whole chain becomes invalid.

⛏️ What’s the Deal With the Nonce?

This is where the “mining” part comes in.

Before a new block can be added, someone (a miner) has to solve a math puzzle:

“Find a number (nonce) that, when you hash this whole block, gives a hash that starts with a bunch of zeros.”

That’s it. It’s brute-force trial and error. Over and over, until the hash meets the difficulty rule.

Why? Because it takes real computing power. That’s what keeps the network honest. It’s expensive to cheat, but easy for everyone else to verify your work.

🌐 No Servers. No CEOs. Just Code.

So here’s the mind-bending part:

There’s no central server. No domain name. No admin panel.

Instead, crypto networks are made of thousands of peer-to-peer nodes. Every full node keeps a full copy of the blockchain and runs the same rules.

When you send a transaction (like “Alice pays Bob”), it gets broadcast to one node, then gossiped across the whole network. Miners pick it up, include it in a block, and — if the block wins — everyone accepts it.

🚀 So How Did This Start?

Back in 2009, Satoshi Nakamoto released the first version of Bitcoin. It included:

• The first block (called the genesis block)
• The P2P networking logic
• Mining rules
• A wallet

Satoshi ran the first node. Then others joined. It went from a solo project to a decentralized network. And it’s never stopped running since.

💡 And Now? Smart Contracts, DeFi, NFTs, You Name It

Modern blockchains like Ethereum let you do a lot more than just send money.

You can write smart contracts — little programs that run on the blockchain. They’re public, immutable, and triggered by transactions. Think: serverless functions with money attached.

That’s how we get:

• Decentralized finance (DeFi)
• DAOs
• NFT marketplaces
• Games, identity systems, and way more

🧠 Final Thoughts

So what is crypto?

It’s a decentralized, secure, programmable database — owned by no one, verified by everyone, and built entirely on code.

At Fitted Tech, we help companies who are curious about blockchain take their first (or next) step — whether it’s integrating smart contracts, launching an NFT product, or just understanding what’s real and what’s hype.

Curious how crypto could fit into your business?
Let’s talk. Visit FittedTech.com and start a conversation — we’re not here to sell you buzzwords. We’re here to build things that work.