Many people think that Bitcoin is a very confusing thing, but Bitcoin is something that is simple to understand.
Based on a journal written by the discoverer (reported in Bitcoin.org), actually Bitcoin is:
A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution.
Have you ever imagined how the system of transactions (selling, buying, money transfer) occurred? Yes there is always a third party to mediate, eg: bank (interbank transfer), Visa, Mastercard, Paypal and so forth.
Did you (from Indonesia) ever buy items on Amazon or Paypal? What does the payment system overseas look like? Example You are using a Visa credit card existing logo.