Development delay is when children have a naturally postponed cognitive and physical progression- when a child is showing delay in more than one milestone. These turning points are basically classified as motor, speech and cognitive skills, and social and emotional development. Not all individuals display the same slow uptake of certain skills. Some children might be able to adapt in a scenario faster than others, and their development delay could show up in later years. The children that are slow learners might be easier to aid. Mostly the delay is in relation to one certain aspect or condition; such as Fragile X syndrome or other chromosomal anomalies.
Nonetheless, it might be somewhat difficult to identify the basic condition.