There are dichotomic and trichotomic classifications of sentences. In a dichotomic classification we see a simple ( one –axis) sentence and a composite sentence.
The trichotomic classification remains the prevalent scheme of the structural classifications of sentences in all linguistic schools (the simple sentence, the compound sentence, the complex sentence with structural variations). Descriptivists introduced the terms a single free utterance (minimal and expanded)( I want a cat), a duplication (or a multiplication) of the pattern (He was young, the weather was beautiful, and Europe was at war) M. Helprin. A Soldier of the Great War. P.178), a sequence with included utterances ( We don’t know where we’ ll be tomorrow).
A composite sentence is a polypredicative structure based on coordination (parataxis), subordination (hypertaxis) or specification (explication).
Composite sentences based on coordination are called compound sentences, while sentences based on subordination are called complex sentences..
Composite sentences based on specification (explication) carry two parts which are separated by a colon, the second part specifying the first (Ïå÷àëåí ÿ: ñî ìíîþ äðóãà íåò. Real grief is ugly: the business of an actor is to represent it not only with truth but with beauty. Women in their nature are giantesses: they will break through everything and go on with their own lives).
The nature of composite sentences with specification is debated. It is not clear whether it is a variety of complex sentences or an independent syntactic connection along with coordination and subordination.A compound sentence can be complicated by subordination, likewise complex sentence can be complicated by coordination:All that I ask of you in return is that you will be a true lover, for Love is wiser than Philosophy, though he is wise, and mightier than Power, though he is mighty (It is a fusion of an allegory with a personified metaphor)
In English subordination domineers over coordination, while in Russian coordination domineers over subordination, be it a simple or a composite sentence.