The WTO replaced GATT as an international organization, but the General Agreement still exists as the WTO’s umbrella treaty for trade in goods, updated as a result of the Uruguay Round negotiations.
Trade lawyers distinguish between GATT 1994, the updated parts of GATT, and GATT 1947, the original agreement which is still the heart of GATT 1994. Confusing? For most of us, it’s enough to refer simply to “GATT”.