What is the difference between an altcoin and a cryptocurrency?

@paolo.leuschke 

The terms "altcoin" and "cryptocurrency" are related but not synonymous.

1. Cryptocurrency: This is a digital or virtual form of currency that uses cryptography for secure financial transactions and to control the creation of new units. Bitcoin was the first cryptocurrency, introduced by Satoshi Nakamoto in 2009, and it operates on the principle of a decentralized peer-to-peer network, known as a blockchain.
2. Altcoin: Altcoin is a shortened form of "alternative coin." It refers to any cryptocurrency other than Bitcoin. Altcoins have their own blockchain and some unique features or improvements compared to Bitcoin, such as different consensus mechanisms, privacy enhancements, or governance structures. Examples of altcoins include Ethereum, Ripple, Litecoin, and many others.

In summary, cryptocurrency is a broad term encompassing all digital currencies that utilize cryptography. Altcoin, on the other hand, specifically refers to cryptocurrencies that are not Bitcoin, representing the wide range of alternative digital currencies available.