A dumpster is a large container that is usually used as a communal collecting place for garbage...kind of like node-heaven on E2.
In the US there are 5 standard dumpster sizes, one of which should surely meet most anyone's disposal requirements. The sizes range from 2 cubic yards up to 8 cubic yards and the containers are rectangular in shape. The largest dumpster (8 cubic yard capacity) weighs approximately 1220 pounds empty and measures 66 inches wide x 71 inches long x 81 inches high.1 That is a lot of trash!
All of these dumpsters will have metal sleeves welded onto the sides of the container to allow a garbage truck to insert a set of metal arms into these slots and mechanically lift the dumpster up and over the top or side of the truck, emptying the collected refuse of you and all your neighbors into an even larger mobile trash container for transport to the local dump or landfill.
Evidently the purpose of dumpsters is not evident to everyone because all of the dumpsters in my apartment complex have signs attached that read: "Please put trash INSIDE the dumpster! Thank-you!" Of course, maybe the signs are there to discourage people from leaving "treasures" out for any potential dumpster-divers that may come along.
1 Source: SunsetWaste.com