“Articulation” is another name for speech sound production.
The development of speech sounds begins gradually with an infant’s cooing of vowels and babbling of syllables, to a toddler’s first attempt at words. There is a typical developmental sequence in which children acquire speech sounds. They usually start to learn the consonants which are easier to see and produce, namely the lip sounds, /p, b, m/. These are quickly followed by the acquisition of tongue-tip sounds, such as /t, d, n/.
Children usually begin with consonant + vowel syllables (e.g., me, no) and move to producing consonant + vowel + consonant + vowel syllables (e.g., mama, baby). They then start to acquire the ability to produce consonants at the end of their words (e.g., bat, pan). Children continue to refine their speech, saying more-difficult sounds as their verbal motor systems become more coordinated.