They all basically do the same job. Some are waterproof most are not.
You can not apply CBU to a concrete floor, there is no reason to do so.
In another thread you have asked someone to write a contract specification for you, which ain't likely to happen here. If you would keep all of your questions related to this one project in the same thread there will be much less confusion. There is no reason for you to have three threads at this time on the same project.