There are lots of different ways that speech, language and communication needs are described and the terminology can sometimes be confusing. An example of this is language delay versus a language disorder.
Language Delay: It is just as it sounds- a delay in a child's speech and language development compared to the chronological age and cognitive/intellectual age of their peers. When a child is learning to talk they follow particular patterns, and gain certain skills at certain ages. A child with a language delay may exhibit a slower onset of language skill, the sequence in which the language skills are learned, rate of progression or all the above.
Example: When a child is around 18 months a child should have a vocabulary of 5-20 words and should be able to refer to some people and objects by specific names. If, at 18 months, a child still isn't speaking any words and doesn't recognize some people by name they may be experiencing a language delay.
Language Disorder: This term is used to describe language development that does NOT follow the usual pattern or sequence that children gain certain skills. The child's language may be developing in an unusual pattern or differently that their peers of the same age. Children with a language disorder have difficulty forming with their words and sentences and their language sounds different than that of their peers.
Example: Receptive language issues involve difficulty understanding what others are saying. Expressive language issues involve difficulty expressing thoughts and ideas. Childhood Apraxia of Speech.
Intervention for a language disorder and delay is child specific and based on that child’s current level of language functioning, The overall goal of intervention is to stimulate language development and teach skills to enhance communication and access academic content.
I hope this cleared up some confusing clinical terminology!