The concept of Species is the same throughout the entire natural world
whether it is Eubacteria, Fungi or Animalia.
    First the latin meaning of the word Species translates to "Kind"  or
"Apperance".
 A species is defined as a population or a group of populations whom exhibit
similar characteristics,and interbreed with each other, producing
viable,fertile offspring.  The key word is Fertile!
 Some basic Definitions;
 Population.... A number of individuals of the same species that occupy the
same area.
 Organism.... any living thing
 Living thing.... Anything that displays order and does work etc......
 Work.... Ability to transfer or convert energy (following first law of
thermodynamics )
 First Law of thermodynamics.... Energy can not be created nor destroyed..
only transferred of converted
 
I'll bet that was more than you needed to hear
 
Sarah Watson