Titles in the Complete series combine extracts from a wide range of primary materials with clear explanatory text to provide readers with a complete introductory resource. This chapter focuses on Article 101(1) TFEU, which prohibits agreements between undertakings, decisions by associations of undertakings, and concerted practices that may affect trade between Member States, and which have as their object or effect the prevention, restriction, or distortion of competition within the internal market. All three elements must be satisfied to establish a breach of Article 101(1). This chapter also considers the implications of the new Commission Notice on Agreements of Minor Importance (de minimis) (2014).