#XRP
A **blockchain** (or chain of blocks) is a **decentralized digital ledger** that stores transactions in a **secure, transparent, and immutable** manner. It is the technology behind cryptocurrencies like **Bitcoin**, but it also has applications in various other areas.
### **How does it work?**
1. **Blocks**: Transactions are grouped into **blocks**.
2. **Chaining**: Each block contains a **hash** (unique code) of the previous block, forming a **chain**.
3. **Decentralization**: The network is maintained by **nodes** (computers) that validate transactions (consensus).
4. **Immutability**: Once recorded, a block **cannot be altered** without invalidating the entire chain.
### **Main characteristics**
✅ **Decentralized**: No control by a single entity (like banks).
✅ **Transparent**: All transactions are public (in open blockchains).
✅ **Secure**: Uses **cryptography** to protect data.
✅ **Immutable**: Recorded data **cannot be changed**.
### **Applications beyond cryptocurrencies**
- **Smart contracts** (Ethereum)
- **Product tracking** (logistics)
- **Electronic voting**
- **Property registration**
- **Health** (secure medical records)
### **Advantages**
🔹 Eliminates intermediaries (lower costs).
🔹 Greater security against fraud.
🔹 Transparency and auditability.
### **Challenges**
🔸 Scalability (limitation on transactions per second).
🔸 Energy consumption (in some blockchains like Bitcoin).
🔸 Uncertain regulation in many countries.
