The toilet base is the actual base of the entire toilet system. The base is the porcelain part of the toilet that makes contact with the ground. This piece may look simple on the outside, but it actually interacts with quite a bit of parts, both interior and exterior. Depending on if the toilet is wall mounted or floor mounted, there may be two or more bolts holding the toilet sturdily into the ground, to avoid tipping or shaking. The base of the toilet also contains the wax rings, the p-trap and drain pipe exit areas, and the exit areas into the internal plumbing system.
It is vital that the toilet base be securely attached to the floor, as a loose base is prone to cracking and to the build-up of bacteria and mold. As the toilet floor is usually the area with the most germs, these germs tend to congregate around the base of the toilet. Every time you clean the inside of your toilet, it is recommended to also spray disinfectant and scrub the floor around the base and the base itself, as well as around the bolts that hold the toilet in place.