You can store all your static resources such as static scripts, audio/video files, images, and attachments in standard storage in COS, which features unlimited capacity and high-frequency reads/writes to provide scalable and reliable storage for static resources and reduce pressure on resource servers. In addition, static resources in COS can be connected to CDN for fast global delivery to clients.
When COS serves as an origin server of CDN, billing consists of two parts: CDN billing (for acceleration) and COS billing (for origin-pulling).
When CDN obtains resources from a nearby CDN node and delivers them to clients, the traffic consumed will be charged by CDN. For more information, please see CDN Billing.
When CDN pulls resources from a COS origin server, the traffic consumed will be charged by COS. For more information, please see COS Billing.