PDM is the business function within PLM (Product Lifecycle Management) that is responsible for the creation, management and publication of product data. The information includes engineering data such as CAD (Computer-Aided Design) models, drawings and their associated documents.
PDM uses CAD tools to create parts lists (Bills of Materials - BOM). The PDM and BOM data is used in ERP (Enterprise Resource Planning) systems to plan and coordinate all transactional operations of a company (sales order management, purchasing, cost accounting, logistics, etc.)