3D printing has been around for over twenty years now, but recently it has gained a lot of attention through the media. This attention has done wonders for the industry by inspiring designers and hobbyists to consider the great options that 3D printing presents.
Most desktop computers have plenty of computing power to create 3D digital models. There is a large array of software available to design with targetting all levels of ability and requirments, like Google SketchUp or Autodesk 123D.
It is often said that '3D printing is cheap', this is very true compared to other methods of producing one off items. Most manufacturing methods involve relatively expensive setup and tooling costs.
In 3D printing, there are no tooling or set up costs, only material costs. Materials for printing are more expensive but for prototypes and small runs there is normally significant savings over other production methods.
There is a large variety of materials that can be used in 3D printing. The most popular materials are plastics, all types of plastic have different properties but the majority of printers run on ABS or PLA filament.