Bitcoin is a new currency that was created in 2k9 by anperson using the name Satoshi Nakamoto.Transactions are made directly means no banks.
If you want to buy bitcoins go this way.
1.Earn Bitcoins by accepting them as a means of payment
2.Earn free Bitcoins by completing tasks on websites
3.Earn Bitcoins from interest payments
4.Earn Bitcoins from mining
5.Earn Bitcoins by getting tipped
6.Earn Bitcoins through trading
7.Earn Bitcoins as a regular income
There is one more way to cash out bitcoins by using an exchange service allowing you to instantly convert your digital currency into money. You will need to choose what currency you have, its amount and what currency you want to get for it
Once you sell your bitcoins, you will need to withdraw your money from the account on the site to your bank account to be able to use it. you can use coinbase for getting cash with highest available rates of Bitcoins.you will send your bitcoin to coinbase and than you can transfer the funds to the bank accounts.