Electronic data processing has become commonplace. To aid the layman to understand his relationship to his new technology, this book provides a concise account of the role of the computer, how it came into being, and what physical equipment is included in today's advanced computer systems. The book discusses machine languages and codes, the binary system, bits and cores, punch cards, magnetic tapes, disks and thin film memories, and various data communications devices. The process of programing a computer is described and the procedures performed by a computer are listed. A glossary and subject index are appended. (JY)