Bitcoin is a digital currency that was created by Satoshi Nakamoto in 2009.It is created electronically and impossible to control it.This currency are not printed currency like dollars or euros.Running computer all around the world are producing it.Owing to this reason they are different from other currencies.
By any measure, Bitcoin was, is, and will be the most sure investment when it comes to cryptocurrency. The key part of such success is popularity, trust and gained due to the fact that Bitcoin was the first cryptocurrency. The more people get to know about Bitcoin, the more it grows.
Altcoin means alternative coin. What do you think, is alternative good or bad? It can be both, so are the Altcoins. There are dozens of moderate and even low-grade coins that only a narrow circle of people know and use. However, certain alternatives create a strong competition for Bitcoin and one of the example is Ethereum because ETH is being the second after Bitcoin cryptocurrency.