There are many classifications of suppliers. According to the products supplied by suppliers, they can be divided into direct material suppliers, indirect material suppliers, and service suppliers.

1. Direct materials: including raw materials, plastics, hardware, electronics, electromechanical, packaging materials and other categories of suppliers.

2. Indirect materials: including suppliers of equipment, maintenance, decoration, and office supplies.

3. Service categories: including software services, technical support, training and other service providers.