Interior design is best described as a form of art. If you hire a decorator to bring some magic and new sense into your home, and he claims to be an artist, you just nod your head in agreement. The aim of interior design is not just to decorate. Decoration and design are inherently different terms that should not be mistaken as one and the same. For example, you decorate your Christmas tree, you don't design it. You can decorate your baby's crib by adding some rotating stars and planets on top, miraculously hanging by a thin string masterfully engineered somewhere in China.
Interior design has feelings attached to it. It is often a combination of related projects, rather than just one (putting the star on the Christmas tree). The aim of those activities is to create human emotion by effectively setting up an interior space. Think of aesthetics combined with healthy living. Interior design is supposed to offer solution to stress relief by presenting you, or the occupants of a home, with an interior that can enhance their way of life.
In broad terms, the goal is to follow a systematic and well coordinated methodology in order to achieve an end goal. This often includes integration of knowledge in relation to creative design, the conduction of extensive research, and analysis. Interior designers look into a person's culture, way of life and understanding of nature before they even suggest a reformation of a home. The goals of interior design are to satisfy both the eye and the soul. Rarely, the goal is to have other people come into your home and sigh at your walls and furniture. Rarely, a member of the humane society would use tiger skin as a carpet just so other people can admire it.
Back in the day, interior design was mostly available to the aristocracy. Maximizing or modifying the external space was not something regular folks would have considered. The game has changed though. Nowadays everyone tries to make their homes attractive, and the easiest way to do so is by modernizing it.
This is where modern interior design comes in. "Modern", in this sense, can be recognized by its clean and unadorned interior. High end furniture is made of plywood, wood, leather and linen materials. It is often made to stand open and raised off the floor, giving you an airy sensation. Coffee tables are made in aerodynamic shapes, often not giving you the chance to place a coffee cup on them. Rugs are non-existent, unless they are neutral colours (black or white) and are placed in one corner of the room. Hardwood floors are the industry's winners when it comes to modernity.
What I find difficult to cope with, is that modern interior design is not very sensual, it is cold. When I walk into a home and I feel the hard and cold hardwood under my feet, I can't help it but think about the nice large rug that I have at home. Space-shaped furniture also does not help make me feel at home. Sure, it looks good and interesting, but so did people's heads butchered on pikes a few hundred years ago.