Computer-aided design (CAD) is the use of computers (or workstations) to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing. Designs made through CAD software are helpful in protecting products and inventions when used in patent applications. CAD output is often in the form of electronic files for print, machining, or other manufacturing operations. The terms computer-aided drafting (CAD) and computer aided design and drafting (CADD) is also used.
Its use in designing electronic systems is known as electronic design automation (EDA). In mechanical design it is known as mechanical design automation (MDA), which includes the process of creating a technical drawing with the use of computer software.
CAD software for mechanical design uses either vector-based graphics to depict the objects of traditional drafting, or may also produce raster graphics showing the overall appearance of designed objects. However, it involves more than just shapes. As in the manual drafting of technical and engineering drawings, the output of CAD must convey information, such as materials, processes, dimensions, and tolerances, according to application-specific conventions.
CAD may be used to design curves and figures in two-dimensional (2D) space; or curves, surfaces, and solids in three-dimensional (3D) space.: 71, 106
CAD is an important industrial art extensively used in many applications, including automotive, shipbuilding, and aerospace industries, industrial and architectural design, prosthetics, and many more. CAD is also widely used to produce computer animation for special effects in movies, advertising and technical manuals, often called DCC digital content creation. The modern ubiquity and power of computers means that even perfume bottles and shampoo dispensers are designed using techniques unheard of by engineers of the 1960s. Because of its enormous economic importance, CAD has been a major driving force for research in computational geometry, computer graphics (both hardware and software), and discrete differential geometry.
The design of geometric models for object shapes, in particular, is occasionally called computer-aided geometric design (CAGD).
South Yorkshire is a ceremonial and metropolitan county in England. It is the southernmost county in the Yorkshire and the Humber region and had a population of 1.34 million in 2011. It has an area of 1,552 square kilometres (599 sq mi) and consists of four metropolitan boroughs, Barnsley, Doncaster, Rotherham and Sheffield. South Yorkshire was created on 1 April 1974 as a result of the Local Government Act 1972. Its largest settlement is Sheffield.
Lying on the east side of the Pennines, South Yorkshire is landlocked, and borders Derbyshire to the west and south-west, West Yorkshire to the north-west, North Yorkshire to the north, the East Riding of Yorkshire to the north-east, Lincolnshire to the east and Nottinghamshire to the south-east. The Sheffield Urban Area is the tenth most populous conurbation in the United Kingdom, and dominates the western half of South Yorkshire with over half of the county's population living within it. South Yorkshire lies within the Sheffield City Region with Barnsley also being within the Leeds City Region, reflecting its geographical position midway between Yorkshire's two largest cities.
South Yorkshire County Council was abolished in 1986 and its metropolitan boroughs are now effectively unitary authorities, although the metropolitan county continues to exist in law. As a ceremonial county, South Yorkshire has a Lord Lieutenant and a High Sheriff.
South Yorkshire was created from 32 local government districts of the West Riding of Yorkshire (the administrative county and four independent county boroughs), with small areas from Derbyshire and Nottinghamshire.