• Object Storage Service

  1. Help Center
  2. Object Storage Service
  3. User Guide
  4. Product Introduction
  5. Basic Concepts
  6. Bucket


On OBS, buckets are containers that store objects. OBS provides flat storage methods in the form of buckets and objects. All objects in a bucket are at the same logical layer, eliminating the traditional multi-layer directory structure of file systems. For details about an object, see Object.

OBS has the following storage classes: Standard, Warm, and Cold. When creating a bucket, you can set a storage class for the bucket. The storage class of a bucket can be changed when needed, meaning OBS can meet all customers' requirements on storage performance and costs.

On OBS, each bucket name must be globally unique and, once set, cannot be changed. When a bucket is created, its access control list (ACL) is generated by default. The ACL records authorized users' permissions such as the read and write permissions. Only authorized users can perform bucket operations, such as creating, deleting, viewing, and setting ACLs for buckets.

An account can create 100 buckets. The number and total size of objects in a bucket are not restricted. Users do not need to worry about system scalability.

As OBS supports HTTP and HTTPS, you can use URLs to locate resources in OBS.

Figure 1 illustrates the relationship between objects and buckets.

Figure 1 Relationship between objects and buckets