Classification

Nomenclature
The naming of species and other taxa follows a set of rules, the International Code of Botanical Nomenclature (ICBN) for plants, the International Code of Zoological Nomenclature (ICZN) for animals.
Some general rules for nomenclature:
1. All taxa must belong to a higher taxonomic group. Often a newly discovered organism is the sole species in a single genus, within a single family ....... etc.
2. The First name to be validly and effectively published has priority. This rule has caused numerous name changes, especially with fossil organisms: Brontosaurus is invalid, and the correct name for the big sauropod dinosaur is Apatosaurus, Eohippus (the tiny "dawn horse") is. invalid and should be referred to as Hyracotherium. Sometime, however, names can be conserved if a group of systematists agrees.
3. All taxa must have an author. When you see a scientific name such as Homo sapiens L, the L stands for Linneus, who first described and named that organism. Most scientists must have their names spelled out, form example Libopollis jarzenii Farabee et al. (an interesting fossil pollen type I stumbled across a very long time ago!).
The Kingdoms of Life
Linnaeus originally placed all living things into either the plant or animal kingdoms. As scientists learned more about the biology of many organisms, this constraining into two kingdoms became less and less defensible.
Evolutionary theory and the cell theory provide us with a basis for the interrelation of all living things. Wa also utilize Linneus' hierarchical classification system, adopting (generally) five kingdoms of living organisms. Viruses, are not considered living. Recent studies sugges\ that there might be a sixth Kingdom, the Archaea.
Monera :-
Monera are the only kingdom composed of prokaryotic organisms, they have a cell wall, and lack both membrane-bound organelles and multicellular forms. The Archaebacteria, the most ancient of this kingdom, are so different that they may belong to a separate kingdom. Other groups of Monera include the cyanobacteria (autotrophic) and eubacteria (heterotrophic).
Protista :-
The most ancient eukaryotic kingdom, protists include a variety of eukaryotic body (single-celled-colonial-multicellular) and nutritional heterotrophic, autotrophic, and both) forms. Perhaps they are best defined as eukaryotes that are NOT fungi, animals, or plants.
Fungi :-
Fungi are a eukaryotic, heterotrophic, usually multicellular group having multinucleated cells enclosed in cells with cell walls. They obtain their energy by decomposing dead and dying organisms and absorbing their nutrients from those organisms. Some fungi also cause disease (yeast infections, rusts, and smuts), while others are useful in baking, brewing, as foods, drugs and sources for antibiotics.
Plantae :-
Plants are immobile, multicellular eukaryotes that produce their food by photosynthesis and have cells encased in cellulose cell walls. Plants are important sources of oxygen, food, and clothing/construction materials, as well as pigments, spices, dyes, and drugs.
Animalia :-
Animals are multicellular, heterotrophic eukaryotes that are capable of mobility at some stage during their lives, and that have cells lacking cell walls. Animals provide food, clothing, fats, scents, companionship, and labor.