Building material is any material which is used for construction purposes. Many naturally occurring substances, such as clay, rocks, sand, and wood, even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacture of building materials is an established industry in many countries and the use of these materials is typically segmented into specific specialty trades, such as carpentry, insulation, plumbing, and roofing work. They provide the make-up of habitats and structures including homes.]citation needed[
Homogeneity and heterogeneity are concepts relating to the uniformity in a substance. A material that is homogeneous is uniform in composition or character; one that is heterogeneous is distinctly nonuniform in one of these qualities.
The concepts are the same to every level of complexity, from atoms to populations of animals or people, and galaxies]clarification needed[. Hence, an element may be homogeneous on a larger scale, compared to being heterogeneous on a smaller scale. This is known as an effective medium approach, or effective medium approximations.
Hospitality is the relationship between the guest and the host, or the act or practice of being hospitable. This includes the reception and entertainment of guests, visitors, or strangers.