Bitcoin is a digital currency created in 2009. Yes, it is a currency and is completely digital. There are no physical bitcoins, only balances kept on a public ledger in the cloud, that – along with all Bitcoin transactions – is verified by a massive amount of computing power. So basically Bitcoins are just set of few numbers or codes backed by complicated mathematical problems, which is reflected on the public ledger you hold in a digital wallet.
So if you own some Bitcoins, then it will reflected on the ledger of your digital wallet, that is the all and the only proof you have of owning the currency.