Terminology

Intonation
Intonation is stress or pitch in pronunciation. It is a verbalization of speech. It is also the rise and fall in pitch of the voice in speech.

Pronunciation
Pronunciation is a style of speech or an articulation of message. It is the act or manner of pronouncing something.

Syllable
A syllable is a unit of sound composed of a central peak of sonority (usually a vowel) and the consonants that cluster around this central peak. It is also a unit of organization for a sequence of speech sounds.

Diphthongs
A diphthong is a new sound produced after combining two different vowels. Vowel 1 + Vowel 2 = new sound (combination of 2 vowels