Phonology studies the way in which phonetic elements function in
a language, the way in which phonemes are organized in a given
language, i.e. their combinatorial possibilities. The phoneme is the
minimal unit in the sound system of a language.
Orthography is very closely connected with phonetics, which in
its turn is connected with lexicology, grammar and stylistics. Because
of the notoriously confusing nature of English spelling, it is particularly
important to think of English pronunciation in terms of phonemes
rather than letters of the alphabet.