This lecture covers the essential aspects of sales contracts, focusing on specific contracts under Swiss law. It begins with the definition of a sales contract, highlighting the obligations of both the seller and the buyer. The instructor explains the scope of sales contracts, including movable and immovable goods, and discusses international sales under the UN Convention on Contracts for the International Sale of Goods (CISG). Key risks for both parties are identified, such as payment obligations for the seller and delivery issues for the buyer. The lecture also addresses the importance of warranties, the transfer of ownership, and the necessary forms for different types of goods. The instructor emphasizes the significance of representations and warranties in contracts, providing examples of potential defects and remedies for breach of warranty. A case study is presented to illustrate how to construct requirements in a sales contract, including warranties and indemnities. The session concludes with a discussion on the implications of contract breaches and the importance of clear contractual terms.