Containers provide a logical grouping for blobs stored in the Windows Azure Blob service. When you upload a blob to the Blob ...

Containers provide a logical grouping for blobs stored in the Windows Azure Blob service. When you upload a blob to the Blob service, you must specify a container for that blob.
The container forms part of the URI that uniquely identifies the blob.
Use the Containers page in your Storage Account to create a new container, view its contents, configure its properties and metadata, or delete the container.