Civil engineering is about the design, construction and maintenance of human-made structures and/or natural structures in the environment through the use of physics and mathematics. Actually, civil engineering includes many subcategories such as environmental engineering, geotechnical, structural, biomechanics, nanotechnology, transportation and many more.
The purpose of having civil engineers are to design the properties of the structures, such as its ability to support its own weight and the materials used for the manufacturing of it. For example, a water treatment plant can be made to aid in the purification of water to help people in developing countries obtain clean water; and civil engineering will aid in deciding the pressures, temperatures, material and other properties of the strucutre to ensure that it lasts long and strong. This is the differences between an architect and a civil engineer. The architect would play a greater part in designing how the building/structure would look and its purposes while the civil engineer would pay more attention to the background of how everything will work out.