Around the world, you'll find that most toilets are made of porcelain, a ceramic-based material that's very smooth to the touch. Toilets aren't made out of porcelain for no reason, however, and the ceramic material they're made of presents several benefits.
Porcelain is easy to clean and its lack of pores makes its surface very smooth. Because it's so smooth, there are no cervices or imperfections where particles can get stuck.
Because of porcelain's nonporous nature, it is not as susceptible to bacterial build up as other materials. This bacteria resistance is especially important in an area like the bathroom, where germs can run rampant.
Porcelain can be easily molded into a variety of shapes and sizes, making it ideal for the complex bowl-shapes that toilets require, as well as for molding the drains, lids and tanks.
From a decorative standpoint, porcelain can be made in a variety of different colors to perfectly match the aesthetic of any bathroom.
Porcelain does not corrode or oxidize like other materials may, meaning that toilets made of porcelain will last a long time without corroding or developing any annoying rust.