Lighting is a fundamental part of everyday life. The sun provides natural light which illuminates the world and gives us sunlight during the day. Artificial lighting, which can be made from electricity, propane tanks, oil, or gas, supplements the sunlight and provides light in dark environments. Lighting has many practical uses such as providing visibility while driving after dark and illuminating work spaces. Lighting also affects human psychological well-being: too much or too little light can cause stress or depression. Artificial lighting can also be used to create or enhance certain moods in a room or area such as a romantic setting or a relaxed atmosphere. Lighting is also an important aspect of interior design. The type and placement of lighting can dramatically change the look and feel of a room. Different shades of light can even be used to accentuate different features in a room such as artwork and bookshelves. Lighting is a versatile and important tool in everyday life. Whether it is for practical, mood-setting or decorative purposes, lighting can be used to create a range of different atmospheres and activities.