Among the many other altcoins that were launched after Bitcoin, Monero is one cryptocurrency which is private, secure and untraceable. Its open source database is easily accessible to all. You are the only one in control of your funds and your account details and transactions are kept hidden from public eyes.
Monero runs on the CryptoNote protocol and was first launched by BitcoinTalk in September 2014 under the name BitMonero. It is a decentralized digital currency and all transactions on this network are validated by distributed consensus. These verified transactions are then chronicled on the blockchain. Monero removes all possibilities of third party encroachment and keeps the network safe via ring signatures, confidential ring transactions as well as stealth addresses to obliterate the amounts, origins or destinations of all XMR transactions. Monero is fully fungible, which comes as a default feature. The focus on privacy has, however, encouraged illegal transactions by people who wish to evade the laws. The Monero mining process opened new doors for legitimate users as well as cyber criminals who would secretly embed the XMR mining code into apps and websites.
The Monero blockchain ensures privacy in 3 ways. The Ring signatures make sure that the identity of the sender is hidden, the stealth addresses ensure that the receiving address of the payment is hidden, and the RingCT ensures that the transaction amount is also hidden. Monero is thus known to be "private, optionally transparent".
The underlying principle which works for Monero mining is known as PoW or Proof-of-Work. Here, the miner is rewarded whenever he or she answers the complex mathematical equations correctly and resolves a block during the process of mining. So for every 120 seconds, a new block is generated in the blockchain.
Speculators and monetary experts have criticized Monero when it first hit the market. The main point of contention for Monero was that it was providing too much of anonymity to the transactors, much to the displeasure of the authorities. It was also said that the only people whom this cryptocurrency would help would be drug lords and prostitution racketeers. But in the long term, the speculators were not proved right and the rapid growth in the capitalization of Monero which rose in the year of 2016 brought many institutional investors to its realm.