In SAP environments, the Sales and Distribution (SD) module manages core activities from capturing customer orders through to product shipments and invoicing. Central to keeping these operations seamless is master data, which serves as stable reference information that changes infrequently yet supports every transaction. Within SD, this encompasses customer profiles, material specifications, pricing configurations, and similar elements. Solid master data prevents common pitfalls like pricing mistakes or shipment holdups early in sales workflows. For those stepping into SAP systems, understanding SD master data proves essential, as consultants use it routinely to tailor setups that align with actual business demands. Let's explore the primary categories, their configurations, and practical roles in daily SD tasks, based on established SAP approaches in various system versions.