Virtual currencies. Like fiat currency, virtual currencies such as Bitcoin, Litecoin, and Ether are intended as a medium of exchange that enables two parties to transact business. But there are important differences: No physical coins or bills. Virtual currencies exist only in computer code. Except for visual representation of Bitcoin and altcoins in advertising and displays, and coin-like tokens that may be produced for marketing purposes, there are no actual coins or bills. Not legal tender. Virtual currencies are not legal tender and are not issued or backed by a government. However, many virtual currencies, which are called convertible virtual currencies, can be redeemed for fiat currency on a number of exchanges. No regulation. Virtual currencies are not regulated by any government agency or authority. However, regulation is being considered, especially where virtual currencies function as securities when they’re used to raise capital and when traded on exchanges.
Altcoins also sometimes differ in the method of verification used to authenticate transactions. While some altcoins use Proof-of-Work systems, others use Proof-of-Stake consensus, which replaces miners with validators. Proof-Of-Stake mining requires a lot less energy and fewer resources than Proof-Of-Work systems since Proof-Of-Work miners have to do much more ‘work’ to mine blocks.

Bitcoin had rallied 220% in 4Q 2017 and if history repeats itself, Bitcoin could reach $96,355, which could potentially be this cycle’s top.
You can do a number of things with cryptocurrencies, depending on which one you own. On the most basic level, the definition of a cryptocurrency asset is that it can be used to send value from one person to another or to pay for goods and services.