Bitcoin is a digital asset, also known as cryptocurrency. It is the first technology to succeed as a cryptocurrrency and the most widely used. It is decentralized, meaning no central authority that governs it, and it shifts towards privacy. Bitcoin is completely digital and does not take any tangible or physical form.
There is a difference in terms of Bitcoin (first capital letter) and bitcoin (all lowercase). The former refers to the protocol governing the currency, while the latter refers to the currency itself (a unit). Bitcoin network is a group of users communicating with each other as part of the protocol that validates and stores transaction history. The network serves as the substitutes of the central bank, and the currency is built on the principles of computer science, cryptography and economics.
Bitcoin has the inspiration for the blockchain, which is the underlying data structure that stores a permanent history of all transactions. Any information added to it cannot be deleted.
Bitcoin is a cultural revolution rooted in the ideals from Cypherpunks Movement in the late 80s and Libertarians. According to the Cypherpunks, one point of centralization is the financial system. Bitcoin whitepaper or research paper was published by Satoshi Nakamoto in October 2008. He created the first ever decentralized and pseudonymous system for transactions.