It is also a name for the page and a half of indecipherable foreplay used in university physics textbooks before they give you the formula for something. Engineering student: I forgot the formula for the volume of a sphere, but I was able to figure it out from the area of a circle using calculus.
Bacterial is the taxonomy, i.e. the rank-based classification, of bacteria. In the scientific classification established by Carolus Linnaeus, each species has to be assigned to a genus (binary nomenclature), which in turn is a lower level of a hierarchy of ranks (family, suborder, order, subclass, class, division/phyla, kingdom and domain).
Bacteria are single celled microbes. The cell structure is simpler than that of other organisms as there is no nucleus or membrane bound organelles. Instead their control centre containing the genetic information is contained in a single loop of DNA. Some bacteria have an extra circle of genetic material called a plasmid.