myki is a smart card ticketing system used for public transport in Melbourne, Australia. It allows users to travel on trains, trams, and buses by tapping the card on card readers at stations and stops. The system is designed to make public transport more convenient and efficient. Users can load money onto their myki cards and choose between different types of fares, including daily caps and concession rates. The card can be purchased at various locations, including train stations and retail outlets, and can also be managed online through the myki website.