Taxonomy is about the classification and naming of a species. A taxon (pl. taxa) is a group of any rank, such as species, family, class etc. or an organism in that group.  Biological taxonomy is a very complex subject but it helps the understanding of the naming of species. I'll try to make this simple by likening the taxonomy to the organigram of a large corporation. If you find a floor sweeper at the bottom of the organigram, tracing upwards will always lead you to the Chief Executive Officer. Similarly, tracing a species upwards will always lead you to the kingdom in which it is situated. To illustrate this, I'll take the example of the House Sparrow. All living creatures have a binomial (or trinomial) nomenclature for its scientific name, the first word being the Genus, the second one indicating the species within the genus and the third one in trinomial nomenclature being the subspecies. The nomenclature is sometimes followed by the name of the scientist who designated it and the year in which it was done. The scientific name of our Sparrow is therefore Passer domesticus, showing the Genus is Passer and the Species is domesticus. Commonly, the binomial nomenclature is also referred to as the species, but this does not cause confusion. The Genus belongs to a Family, Passeridae, which includes a large number of sparrows in four different Genera (the plural of Genus). In turn, the Family is under the Suborder Passeri, which means a song bird, in turn of the Order Passeriformes, defined as perching birds and representing about half of all the bird species. The Order is under the Class, in this case, Aves which includes all birds, some 10,000 Species. The Class belongs to the Phylum Chordata, meaning loosely the vertebrates but more precisely having a nervous system along the back. The "CEO" is the Kingdom, here Animalia that hardly needs translation of explanation.

There are many examples where the scientific taxonomy is not clear-cut. It may be that one person will consider a species belongs to one taxon but another person may not agree. This may lead to a species having two binomial nomenclatures. Similarly, one person may consider an organism is a species in its own right while another may consider it a subspecies. Only DNA testing can help to resolve these differences but even this may not give a definitive answer. One example is the Cyprus Cedar which has been classified as both Cedrus brevifolia and Cedrus libani brevifolia, the latter being a subspecies of the Lebanese Cedar. .

Capitalisation and italicisation

Conventionally, the binomial nomenclature has the Genus capitalised but not the species or the subspecies. With English names, all the words are capitalised. Thus we say House Sparrow but Passer domesticus.

Equally conventionally, everything from the Genus downwards is written in italic letters, but not the English names.

Endemism

Oxford defines the adjective endemic as "Of a plant or animal: native to, and esp. restricted to, a certain country or area".

I'm not sure whether this definition is strictly accurate. If, for example, we take the Cyprus Wheatear, it is considered an endemic bird because it is known to breed only on the island although it spends the winter elsewhere. This may be a matter of semantics, but it may nevertheless be important.

Cyprus, being an island, has a large number of endemic species and subspecies in nearly every Class and Order. The lack of communication with the mainland is an obvious reason over the last 50,000 years when many Species were developing.

Another related matter is island giantism and dwarfism. It is well known from the remains of bones that Cyprus had dwarf elephants and hippopotami up to about 10,000 years ago. It is probable that naturally selective breeding was the cause of the dwarfism because the size of the island was insufficient to sustain the full-sized animals. Today, a few of the endemic species and subspecies differ from their continental counterparts by their size, possibly for similar reasons.