Learning articulatory skills is a particular type of motor learning that occurs as a developmental process that evolves as the child grows. As the child get older, their motor movement / articulation skills mature and develop - thus, a six year old child will have a broader range of articulatory than a two or three year old child

Children with articulatory difficulty have impaired motor function rather than impairments in central language abilities

Speech Sounds (Phones): sounds that represent physical sound realities used in speech. These sounds differ from other varieties of human sounds (such as coughing or burping) because they provide meaning.