Bitcoin is a digital currency, also known as cryptocurrency. It was invented by Satoshi Nakamoto in 2008.
Bitcoins are not physical objects, they exist in the virtual world as snippets of code, they are used as a decentralized digital currency, which many can benefit from without going through intermediaries for peer-to-peer transactions.
These transactions are verified by network nodes through cryptography and recorded in a public distributed ledger called a blockchain.