I could be here forever explaining the concept behind it so this is why I decided to use "Wikipedia" they have it in a nutshell.
“Interior design is the art and science of enhancing the interior of a building to achieve a healthier and more aesthetically pleasing environment for the people using the space.
An interior designer is someone who plans, research, coordinates, and manages such enhancement projects. Interior design is a multifaceted profession that includes conceptual development, space planning, site inspections, programming, research, communicating with the stakeholders of a project, construction management, and execution of the design".
