What are Cryptocurrencies?
Altcoins are just any cryptocurrency that isn't Bitcoin. Because Bitcoin was the 1st, it will always have it's place as being known as it's own brand as well as another term for cryptocurrency. But Bitcoin does not explain altcoins, because there have been and will be altcoins that make Bitcoin look like a ticket system only. Many other altcoins have made their unique mark in attempting to add more substance to the cryptocurrency world.
By either adding new features to the cryptocurrency wallet, or just having more to the altcoin, to actually using the blockchain for more than just storage and tranfer recording, but DNS records, voting platforms, platforms for other coins and smart contracts to be built on, and it goes on and on and on. You'll be using a future altcoin yet to be concepted or at least developed, that will have multiple facets and features, because the competiton sector will force such or the altcoin will die. You may or may not even know how it works, depending on marketing or interest, but could be a part of society in a multitude of ways where a vast ecosystem of altcoins work in tadem to help run the logistical framework a futurescape would require.
Cryptocurrency information more widely used Altcoins and of course Bitcoin:
This information may change over time, as I remove altcoins that are no longer active or maybe involved in scamming to prevent further people falling prey.
Cryptocurrency is a breakthrough technology, however it's no where near it's peak, the types of features and multi-faceted ability that can be coded into an altcoin is still being tested and pushed, not to mention money to be made both from good intentions and bad. The blockchain and cryptocurrency will be the mediums that many future trends will be built on top of.