$BTC Here's a concise overview of Bitcoin ($BTC) in approximately 200 words, synthesizing key information from the search results:

1. **Definition & Origin**: Bitcoin (BTC) is the first decentralized cryptocurrency, created in 2008 by the pseudonymous **Satoshi Nakamoto**. It launched in January 2009 with the mining of the "genesis block," which embedded a headline criticizing bank bailouts. It operates without central banks or governments.

2. **Technology**: Bitcoin uses **blockchain technology** – a public, tamper-proof ledger maintained by a peer-to-peer network. Transactions are verified by "miners" solving complex cryptographic puzzles (Proof-of-Work). Miners are rewarded with newly created bitcoins and transaction fees.

3. **Supply & Economics**: Bitcoin has a strict **limited supply of 21 million coins**. New bitcoins enter circulation via mining rewards, which undergo "halving" approximately every 4 years (current reward: **3.125 BTC per block** as of 2024). This scarcity is a key design feature. As of July 12, 2025, **1 BTC ≈ R$656,102.51** (BRL), with a market cap exceeding R$13 trillion.

4. **Function & Use Cases**: Bitcoin enables **peer-to-peer electronic cash** transactions globally. It's used for:

* **Speculation/Investment**: Its price is highly volatile but has shown significant long-term growth (historically reaching over $100,000).

* **Store of Value**: Often compared to "digital gold" and used as a hedge against inflation or economic uncertainty.

* **Payments**: Accepted by various merchants, though adoption varies.

5. **Key Concepts**: Ownership is managed via cryptographic **keys** stored in digital wallets. The smallest unit is a **satoshi** (0.00000001 BTC). Transactions are pseudonymous and recorded on the public blockchain.