Cryptocurrency is an increasingly trending term referring to digital money that can be purchased, transferred, and/or sold securely using cryptography, which encrypts and protects the data used to help identify and track cryptocurrency transactions.
Unlike regular currency, which exists in tangible form or is backed by something tangible like gold, cryptocurrency is purely digital money and exists solely in the internet. Additionally, cryptocurrency, also known as cryptocoin, is not backed or managed by an authorized third party like a bank or government.
In other words, cryptocurrency exists as a secure, decentralized form of currency, with cryptocurrency transactions changed and verified by a network of computers that aren’t affiliated with any one single entity.
Crypto currencies are not able to make inroads into daily usage, this is the biggest drawback. Next is it's value fluctuations.