Mainnet release: 3-1-2009
Short explanation: Internet money and by many claimed to be 'digital gold'.
Bitcoin is the original cryptocurrency. Released in early 2009, it is a new form of internet money that is fundamentally different from existing currencies.
It is decentralised, meaning it isn’t controlled by any single company or person, and all transactions are peer-to-peer. The history of all transactions is continually being verified by powerful computers, so it is practically impossible to change once a transaction has been accepted.
This means that anybody in the world is able to buy bitcoin and send money to anybody else, which has never been possible before in such a permissionless manner.
For a comprehensive history you can go the Wikipedia's page here and Bitcoin.com also has a nice history series which you can find here.
The coin found parity with the US dollar on February 9, 2011. Six years later, it would trade at parity with an ounce of gold.
The Father of cryptos, Bitcoin is considered the most secure of the cryptos, partly because it has been around the longest and therefore has the most commercial proof of security, and partly because the amount of computing power and number of nodes providing the protection is the largest.
When Satoshi first created the Bitcoin protocol 10 years ago, the program was created with the C++ programming language. However, the original client’s binary data can conform to any programming language standard, as long as it adheres to the blockchain’s consensus rules.