1- Bitcoin: The first decentralized cryptocurrency. It was launched in 2009 by unknown person called himself Satoshi Nakamoto. The transactions done directly between users without need for middle men, those transactions are secure and can not be hacked because they are recorded in public disturbed computers called the blockchain.There are tow ways to have Bitcoin, either by buying it or by mining. Mining is a competition between people to mine bitcoin by solving very complex mathematical algorithms, using powerful computers, in the end the winner gets 12.5 Bitcoins and the losers should start from zero. There are just 21 million Bitcoins, and nowadays there are 16.7 million in circulation and what remaining are just 4.3 million Bitcoins.
2- Litecoin: It was launched by Charles Lee a former google employee in 2011. The transaction in Litecoin four time faster than the transaction in Bitcoin, it takes 2.5 minutes while it needs 10 minutes in Bitcoin. The limit of Litecoin is 84 million Litecoin which is four time more than the limit of Bitcoin. Litecoin uses more complicated algorithms than Bitcoin and because of that the mining for Litecoin is harder and more expensive than mining for Bitcoin.
3- Ripple: Ripple was released in 2012. It is also a digit currency, but it is very different from other cryptocurrencies. The fundamental differences are:Even though Ripple is decentralized but its supply is controlled by one company.The limit of Ripple is 100 billion, but it can not be mined by users, to company control the process and until now 38 billion Ripple are in circulation and the company can release one billion by month.The transaction is very fast, and it can be done be seconds. Banks like to use Ripple and the number of companies and banks which using Ripple are increasing rapidly.
4- Ethereum: It was launched in 2014 by Vitalik Buterin. The currency of Ethereum called ether and it is does not has limit unlike Bitcoin, also the transaction in Ether can take 15 seconds. The Ether’s limit is 98 million and there are just 10% in circulation, while the mining reward in Bitcoin changes every 4 years, it is stable in Ether. The transaction fees in Ether is lower than the transaction fees in Bitcoin (the average transaction fees in Ether is about 0.33$ while it is around 23$ in Bitcoin).
5- Zcash: It was found by Zooko Wilcox-O’Hearn in 2016. Zcash is similar to Bitcoin as a digital currency, and it has the same limit (21 million), but the main different feature is the more security and privacy that Zcash provides and it likes Ripple controlled by company. In Zcash the users can hide the amount of transaction, sender and the recipient. Also, the mining process is like the process in Bitcoin, but during the first 4 years the company will take 20% from each coin users mine and they will give it to the investors and founders under the name “Founders reward”, and a lot of users do not like this way and they said that is unfair, but the founders said that is the way to found the company to keep developing.
6- Monero: It was released in 2014. Monero is the 13th largest cryptocurrency in the world with a market capitalization of 5.9$ billion dollars. What make Monero very popular is the super anonymity, no one can know the users or the senders or the transactions amount and each unit of the Monero can be substituted by another unit and that is what attracted users who want to hide from law enforcement, and because of that it is the most popular cryptocurrency in North Korea. Also, a lot of Bitcoin’s users using Monero to break the link between transactions so first they convert the Bitcoin to Monero and after that they convert it back to Bitcoin, so the address will be unrelated to the address they used before. Monero want the mining to be egalitarian for all users, and it can be done on normal computers but that’s what make it easier to hack and hackers can embed the mining code into websites and apps without inform users, which will make the user’s computers mining for the hackers will the user is in the website.
7- Bitcoin Cash: It is a hard fork of Bitcoin. The size of Bitcoin’s block (1 megabyte) cause a lot of issues and delay in transactions specially when the Bitcoin prices increased in 2015, and because the block size limit was added to the Bitcoin code to protect the Bitcoin from hacker’s attack, there was no way to increase the block limit because it was not controlled by central company. There were many fork launched such as Bitcoin XT and Bitcoin Unlimited but the all failed, In 2017 Bitcoin cash was released with block size 8 megabytes, and the main goal of Bitcoin cash was to reduce the transaction time and they aim to compete with the visa and PayPal transaction volume.