Microorganisms are diverse, why are they groped together

Microbes are classified into various groups on the basis of their characteristics to make the study easier.

1. the energy lost to disorder metabolism     -entropy

2. related to or possessing motion potential     -kinetic

3. all of the chemical reactions in an organism required for maintenance of the processes of life entropy     -metabolism

4. possible; ability to go into action or perform work kinetic     -potential

5. the study of energy and its transformations thermodynamics     -thermodynamics

not sure if this is what you'r looking for eubacteria and archaebacteria