The purpose of this article is to provide an introduction to vacuum science and technology for absolute beginners. The kinetic theory of gases is briefly described in the initial introductory part. The body of this article is divided into three parts. The first part deals with vacuum pumps. The operation principles are explained for several popular types of vacuum pumps. The second part deals with vacuum gauges. The operations of commonly used vacuum gauges are discussed. The third one deals with vacuum-tight connection with tubes and flanges. Throughout the text, basic concepts and technical terms are explained so that the text can be easily understood even by very beginners. Caution points for using vacuum systems are also given.
