“Universal Design is the design of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design.”
Simply put, the goal for Universal Design is to simplify life by making products, communications and the built environment as usable as possible, by as many people as possible, at little or no cost. 
The concept of Universal Design was first articulated in the 1970’s by architects who responded to an increased awareness of the need to accommodate individuals who have a disability while designing buildings and other public structures. Such designs were ultimately based on a set of principles by which the plans for all new structures would be judged. Thus, new buildings were designed with hallways, elevators and doors wide enough for wheelchairs. Lavatories, drinking fountains and sidewalks were also conformed to similar sets of standards. This benefitted all people, of all ages and all abilities.
 Mace, Ron, The Center for Universal Design, North Carolina State University. https://www.ncsu.edu/ncsu/design/cud/about_ud/about_ud.htm