Bitcoin is a peer-to-peer payment system and digital currency introduced as open source software in 2009. It is a cryptocurrency, so-called because it uses cryptography to control the creation and transfer of money. Conventionally "Bitcoin" capitalized refers to the technology and network whereas "bitcoins" lowercase refers to the currency itself. Bitcoins are created by a process called mining in which participants verify and record payments in exchange for transaction fees and newly minted bitcoins. Users send and receive bitcoins using wallet software on a personal computer, mobile device or on the web. Bitcoins can be obtained by mining or in exchange for products, services, or other currencies.