ABA is a scientific discipline that uses evidence-based procedures to build or change socially significant behavior in an individual. Modern approaches in ABA work with the child's natural motivation so that the learning process itself is rewarding and the child enjoys learning. 

A behavioral analyst is interested in, "Why does behavior change over time?"

He looks for answers in the investigation of biological factors and environmental influences, although he is particularly interested in the influence of the environment on behavior.

Procedures based on the principles of ABA find use in companies, shops, in transport, in homes for the elderly, but it is most widely used in education, where it enables the education of even those children and youth who were previously considered uneducable. Each child is unique in their educational needs and it is up to us to find the most effective way. 

ABA places particular emphasis on the FUNCTION of the behavior = what the given behavior serves the child. Example: A behavioral analyst is interested in what a child is screaming. It can be trying to get something the child wants/trying to escape from something he doesn't want to do/manifesting pain/self-stimulation. Based on the determination of the function of the behavior, an effective intervention can be set up.

ABA works with behaviors that must be observable and measurable. It requires the collection of behavioral records and their repeated examination. It makes changes in the environment to change behavior. The adult is responsible for the progress = we never blame the child when something goes wrong, but we analyze whether the intervention we set was appropriate for the current developmental level of the child, whether the learning procedures and the frequency of practice were followed exactly.