Architecture is both the process and product of planning, designing and constructing space that reflects functional, social, and aesthetic considerations. It requires the manipulation and coordination of material, technology, light, and shadow. Architecture also encompasses the pragmatic aspects of realizing designed spaces, such as project planning, cost estimating and construction administration. Architectural works are often perceived as cultural and political symbols and as works of art. Architects plan, design and review the construction of buildings and structures for the use of people by the creative organization of materials and components with consideration to mass,space, form, volume, texture, structure, light, shadow, materials, program, and pragmatic elements such as cost, construction limitations and technology, to achieve an end which is usually functional, economical, practical and often artistic.