toilet.

A toilet is "a bathroom fixture consisting of a bowl, usually with a detachable, hinged seat and lid, and a device for flushing with water, used for defecation and urination." the dictionary says.
It is a very important invention. We use it everyday.
If it weren't for toilets, deadly diseases would spread around the world, and you would be doing "it" in public...There are different types of toilets:
The normal flush toilet,

a squat toilet,
a public toilet,
a portable toilet,

an outdoor toilet, 
an indoor toilet,

a urinal,

a roman toilet

and a Japanese toilet. 
There are different kinds of toilets around the world in different places, some with big fancy toilets and some with a small, dirty toilet. In the olden days they would just make a whole in the ground and do "it" there, but because of that diseases started to spread. Toilets might not seem as important, when they actually are very important inventions. The toilet bowl is placed in a room called the bathroom. There are other names for this room such as, wash closet, comfort room, toilet, restroom, powder room, and other names. The inventor is anonymous but the guy or girl who made this invention is a GENIUS.