Top 5 Cryptocurrency exists in the World

A cryptocurrency is a digital or virtual currency that uses cryptography for security. A cryptocurrency is difficult to counterfeit because of this security feature. A defining feature of a cryptocurrency, and arguably its most endearing allure, is its organic nature; it is not issued by any central authority, rendering it theoretically immune to government interference or manipulation.

1.Bitcoin
In 2009, Bitcoin was created by an unknown person or group of people under the name Satoshi Nakamoto and released as open-source software. It is the first decentralized digital currency, as the system works without a central bank or single administrator. The network is peer-to-peer and transactions take place between users directly through the use of cryptography, without an intermediary. These transactions are verified by network nodes and recorded in a public distributed ledger called a blockchain.

2. Litecoin
In 2011, Litecoin was created by Charlie Lee, a MIT graduate and former Google engineer. Litecoin is based on an open source global payment network that is not controlled by any central authority and uses "scrypt" as a proof of work, which can be decoded with the help of CPUs of consumer grade. Although Litecoin is like Bitcoin in many ways, it has a faster block generation rate and hence offers a faster transaction confirmation. Other than developers, there are a growing number of merchants who accept Litecoin.
The Litecoin Network aims to process a block every 2.5 minutes, rather than Bitcoin's 10 minutes. The developers claim that this allows Litecoin to have faster transaction confirmation.
Litecoin uses scrypt in its proof-of-work algorithm, a sequential memory-hard function requiring asymptotically more memory than an algorithm which is not memory-hard.
Due to Litecoin's use of the scrypt algorithm, FPGA and ASIC devices made for mining Litecoin are more complicated to create and more expensive to produce than they are for Bitcoin, which uses SHA-256.

3. Ethereum
Ethereum was proposed in late 2013 by Vitalik Buterin, a cryptocurrency researcher and programmer. Development was funded by an online crowdsale between July and August 2014. The system went live on 30 July 2015, with 11.9 million coins "premined" for the crowdsale. This accounts for approximately 13 percent of the total circulating supply.
In 2016, as a result of the collapse of The DAO project, Ethereum was forked into two separate blockchains - the new forked version became Ethereum (ETH), and the original continued as Ethereum Classic (ETC). According to Ethereum, it can be used to “codify, decentralize, secure and trade just about anything.”

4.Zcash

In 2016, Zcash payments are published on a public blockchain, but users are able to use an optional privacy feature to conceal the sender, recipient, and amount being transacted. Like Bitcoin, Zcash has a fixed total supply of 21 million units. In the first 4 years, 20% of the coins created in that period are allocated to a "founders' reward" shared between investors, developers, and a non-profit foundation.

Zcash affords private transactors the option of "selective disclosure", allowing a user to prove payment for auditing purposes. One such reason is to allow private transactors the choice to comply with anti-money laundering or tax regulations. "Transactions are auditable but disclosure is under the participant's control."

5.Dash

Dash aims to be the most user-friendly and most on-chain-scalable cryptocurrency in the world. Dash offers more anonymity as it works on a decentralized mastercode network that makes transactions almost untraceably. Launched in January 2014, Dash experienced an increasing fan following in a short span of time. This cryptocurrency was created and developed by Evan Duffield and can be mined using a CPU or GPU. In March 2015, ‘Darkcoin’ was rebranded to Dash, which stands for Digital Cash and operates under the ticker – DASH.