Bitcoin is a vitrual currency that was developed in 2009 by Satoshi Nakamoto, so this currency is like the Rupiah or Dollar but this bit coin is only available in the digital world.
Bitcoin has an interesting feature because bitcoin can be sent anywhere in seconds, whenever and wherever you want.
For sending capital in bitcoin it takes only a smartphone and an internet connection to transfer bitcoin.
Irreversible Transfers
What is Irreversible? so if you transfer it once can not be canceled, Because Bitcoin is given into someone else's hands, so actually the transaction can be canceled as long as the person is willing to send the Bitcoin back.