I'll write in English for this time, but don't worry, Grandma won't be angry this time! Here's a brief summary:

Cryptocurrencies, such as Bitcoin and Ethereum, are digital or virtual currencies that use cryptography for secure financial transactions. They are decentralized, meaning they are not controlled by any government or institution, and are based on a distributed ledger technology called blockchain. Traditional fiat currencies, such as the US dollar and euro, are physical or digital currencies issued by governments and central banks. Cryptocurrencies have gained popularity in recent years due to their potential for fast and secure transactions, as well as their limited supply, which can lead to increased value. However, they are also known for their volatility and are not yet widely accepted as a form of payment.