To receive and convey information and ideas. What is often thought of as communication is formal, symbolic language, usually speech. Actually, communication can be thought of as occurring on a continuum. On one end is nonsymbolic, unintentional communication, such as a baby's instinctive crying whose meaning can be interpreted by a parent. On the other end is abstract, symbolic communication, such as speech or sign language.
Communication can even be a behavior.
In the past, some children with moderate to severe disabilities were considered too cognitively impaired to learn how to communicate effectively. Currently, it is widely believed that any child, from those with severe and multiple disabilities to those with temporary impairments, can benefit from an AAC program that is appropriate and individualized.