Yes. For more information, see Setting Origin-Pull.
COS and CDN are two different products.
Tencent Cloud Cloud Object Storage (COS) is a distributed storage service designed to store a massive number of files. It allows you to upload, download, and manage files in various formats for storage and management of massive amounts of data.
Content Delivery Network (CDN) consists of high-performance cache nodes distributed around the globe to accelerate internet content delivery. These nodes store your content based on caching policies. When a user makes a content request, it will be routed to the node closest to the user, reducing access latency and improving availability.
You do not have to enable CDN when using COS. Using CDN in COS applies to the following scenarios:
For more information, see CDN Acceleration Overview.
No. If you want to use CDN to access COS with private read/write permission on COS, see CDN origin-pull authentication.
Yes, but you need to be authorized with related configurations first. For more information, see Private-read buckets.
COS itself does not support automatic purging of CDN cache, a feature you should use with the help of Serverless Cloud Function (SCF). For more information, see CDN Cache Purging.
It is recommended that you do not use a CDN acceleration domain name as a custom domain name to upload files, because CDN itself is not used for accelerated upload. You are advised to use the global acceleration feature of COS to accelerate data upload and download. For more information on global acceleration, see here.