I always notice that when an air condition is working and cooling the room it, is heating outside the room and a Liquid is dropping from the other side of the air conditioner. how does this happen and is it drinkable?, what is the name, is it water(H2O)?
At the risk of answering a question that may be better suited in Physics.SE, yes, it's water. It's condensation from the evaporation coil, which is where the refrigerant expands in order to cool the air drawn through the unit. That is how an AC unit also dehumidifies the air.
Chemically speaking, distilled water is drinkable, but it isn't great to drink. It can sap electrolytes from your body over time. From a unit like that, however, it may be contaminated with oils, rust, dirt, etc.