Provider / Supplier / Vendor / External Provider - organization that provides a product  or a service.  EXAMPLE Producer, distributor, retailer or vendor of a product or a service.  Supplier Approval and Evaluation is critical to quality management. Suppliers go by various different terms, from vendor, to external provider and may even be considered an interest party (whole different conversation there).

Key Standards - ISO 9001:2015 8.4 Control of externally provided processes, products and services | API Q1 5.6.1.2 Initial Supplier Evaluation | API Q2 5.6.1.2 Initial Supplier Evaluation