Electronic textiles, also known as smart garments, smart clothing, smart textiles, or smart fabrics, are fabrics that enable digital components, and electronics to be embedded in them. Smart textiles are fabrics that have been developed with new technologies that provide added value to the wearer. E-textiles are an exciting, new field of electronics that combines embedded electronics with fabric and textiles. These wearable electronics are gaining lots of attention and are becoming more accessible to the non-technical crowd by the day. Smart textiles can be broken into two different categories: aesthetic and performance enhancing. Aesthetic examples include everything from fabrics that light up to fabrics that can change color. Some of these fabrics gather energy from the environment by harnessing vibrations, sound or heat, reacting to this input. Then there are performance enhancing smart textiles, which will have a huge impact on the athletic, extreme sports and military industries. There are fabrics that help regulate body temperature, reduce wind resistance and control muscle vibration all of which help improve athletic performance. In general, the development of electronic textiles supports the idea of wearable computing, or electronic devices worked into garment designs. However, there are other applications of electronic textiles, such as interior design technologies, that also rely on integrating electronic components into fabrics or fibers. Within the relatively new industry around electronic textiles, projects are pursued based on various different kinds of functionality. Some electronic textile products may only be built for data storage, while others provide physical interfaces through control elements in the garment design. Although the practical applications of this technology are very new, some projects involving electronic textiles and intelligent garments do exist now. Many of these are aimed at uses within the health care industry, where wearable computing elements can be used to monitor vital signs and otherwise track a persons health in real time. This book, Electronic Textiles, emphasizes on the novelty and usages of smart garments or fabrics in numerous fields.