A steam turbine with the case opened. Such turbines produce most of the electricity used today. Electricity consumption and living standards are highly correlated. Electrification is believed to be the most important engineering achievement of the 20th century. Technology („science of craft“, from Greek τέχνη, techne, „art, skill, cunning of hand“; and -λογία, -logia) is the sum of techniques, skills, methods, and processes used in the production of goods or services or in the accomplishment of objectives, such as scientific investigation. Technology can be the knowledge of techniques, processes, and the like, or it can be embedded in machines to allow for operation without detailed knowledge of their workings. Systems (e.g. machines) applying technology by taking an input, changing it according to the system’s use, and then producing an outcome are referred to as technology systems or technological systems.
The simplest form of technology is the development and use of basic tools. The prehistoric discovery of how to control fire and the later Neolithic Revolution increased the available sources of food, and the invention of the wheel helped humans to travel in and control their environment. Developments in historic times, including the printing press, the telephone, and the Internet, have lessened physical barriers to communication and allowed humans to interact freely on a global scale.