There are many different types of concrete made to day just depends on what you are looking to have done, The company I work at has over 4000 different mixes in our system, for instance there are out side mixes inside mixes mixes for basement floors mixes if you have plastic under you concrete many have air additives witch is a liquid that when added makes tiny air bubbles in the concrete so in the winter when the concrete is wet and it is freezing out side the concrete expands and the air inside the concrete helps to absorb the expansion to help keeping it from cracking and or crumble apart full air is use outside half air is used in garage floors and stoops ect.all in all there are variations in all mixes. concrete is not just concrete anymore.

You may want to consult the American Concrete Institute Standard 318 for the different categories of slabs and how they are analyzed such as one way, two way, waffle, flat panel, etc.

Well let me see, if it is made of concrete it must be concrete, it is not made from concrete it must not be concrete. I would say the answer is one. Unless you would like to further explain this very vague question that is about the best I can do.

Without being TOTALY sarcastic :wet,dry,various shapes and with or without Jimmy Hoffa's body in it.