Bitcoin is virtual currency which has no physical existence that was created in 2009 by an unknown person using the alias Satoshi Nakamoto. Transactions are made with no middle men, meaning, no banks. A transaction is a transfer of value between Bitcoin wallets that gets included in the block chain. Bitcoin wallets keep in a secret piece of data called a private key or seed, which is used to sign transactions, providing a mathematical proof that they have come from the owner of the wallet.
Bitcoin is gaining Popularity like anything, but One should very care full to chose the exchange or source from where bitcoins are being purchased.
There are many exchanges of Bitcoin in world but Zebpay and Coinsecure in India are doing very well in terms and customer support and flawless transactions.