Bitcoin

What is Bitcoin?

Bitcoin is the world's first decentralized digital currency. Invented by the pseudonymous Satoshi Nakamoto in 2008 and launched in January 2009, Bitcoin allows people to send value directly to each other without a bank, government, or any middleman.

The Problem Bitcoin Solves

Before Bitcoin, digital money had a fatal flaw: the double-spend problem. If you send someone a digital file, you still have a copy. How do you prevent people from spending digital money twice? Banks solved this by keeping ledgers — but that required trusting them.

Bitcoin solved this with a public ledger (blockchain) maintained by thousands of computers worldwide. No single entity controls it.

Key Properties of Bitcoin

• Decentralized: No government, bank, or company controls it
• Fixed Supply: Only 21 million BTC will ever exist
• Permissionless: Anyone can use it without asking permission
• Censorship-resistant: No one can freeze or seize your Bitcoin
• Transparent: All transactions are publicly verifiable
• Pseudonymous: Addresses don't require ID verification

How Does It Work?

When you send Bitcoin, your transaction is broadcast to thousands of nodes. Miners bundle transactions into blocks, solve a cryptographic puzzle (Proof of Work), and add the block to the chain. This process takes about 10 minutes per block.

The 21 Million Cap

Bitcoin's code limits total supply to 21 million BTC. New Bitcoin is issued as a "block reward" to miners. This reward halves every 210,000 blocks (~4 years). The last Bitcoin will be mined around year 2140.

Year 2009: 50 BTC per block
Year 2012: 25 BTC (1st halving)
Year 2016: 12.5 BTC (2nd halving)
Year 2020: 6.25 BTC (3rd halving)
Year 2024: 3.125 BTC (4th halving)

"Bitcoin is a remarkable cryptographic achievement and the ability to create something that is not duplicable in the digital world has enormous value." — Eric Schmidt, former Google CEO

Satoshi Nakamoto

The creator of Bitcoin remains anonymous to this day. Satoshi published the Bitcoin Whitepaper in October 2008, launched the network in January 2009, then gradually disappeared by 2011. Their estimated 1 million BTC has never been moved.