GVB (www.gvb.nl) is Amsterdam's public transportation company and it provides integrated metro, tram and bus service throughout the city and its surrounding areas. Since 2010 a comprehensive OV-chipcard ticket system allows you to travel on the metro, trams, buses and even trains using just one card. There are a variety of OV-chipcard options and you can upload them with travel credits at special machines located at stations and even in most supermarkets.
You can purchase OV-chipcards for 24 (€7.50), 48 (€12), 72 (€16.50), 96 (€21), 120 (€26), 144 (€29.50) and 168 (€32) hours, which afford you unlimited travel on all trams, buses, metros and night buses and an economical way to explore the city. A one-hour OV card can be purchased onboard from GVB drivers and conductors, but a premium is charged for this ticket. It costs €2.80 for one hour of unlimited travel on different buses and trains in the city that begins once you board your selected mode of transportation and check in by placing it next to the scanners near the doors. You must also scan your card when leaving the vehicle.