This work may be useful to students, but also to all those interested in studying specialized books that refer to the basic concepts of procurement and supply. The subject developed in the work refers to the purchasing function of the enterprise as a whole, namely its characteristics and peculiarities, but also the tools used in procurement activities. This paper is structured in 7 chapters. Each chapter begins with the study objectives, which allows the students to learn quicker the material. Each chapter finalizes with questions for discussion on the studied topic and a set of tests, which helps students to make a self-assessment of knowledge.