Intellectual disability is a reduced ability to think, comprehend and to learn new skills. Milestones like crawling, walking, talking are all delayed.  There is trouble in understanding social rules, seeing the consequences of their actions and solving problems. Some may have additional problems of seizures, mood disorders, motor skills impairment, vision problems or hearing problems.
Adults with intellectual challenges have a huge potential to be self-dependent and productive provided their training is structured and systematic.
There is a dire need for such trainings because most often it is seen among parents that, due to their work load and time constraints, they are unable to provide the necessary training to their children on basic life skills and thus results in even slower developmental progress among children with intellectual challenges.