Binary Large Object (BLOB) is one of the four core storage services that are secure, scalable and easy to access. Itz the simplest way to store text or binary data with Windows Azure.
As the concept, each storage account has access to blob storage. For each account there can be 0..n containers. Each container contains the actual blobs, which is a raw byte array. Containers can be public or private. In public containers, the URLs to the blobs can be accessed over the internet while in a private container, only the account holder can access those blob URLs.
Each Blob can have a set of metadata set as a NameValueCollection of strings. Key terms are explained in the below list:
Storage Account – All access to Windows Azure Storage is done through a storage account. This is the highest level of the namespace for accessing blobs An account can have many Blob Containers
Blob Container – A container provides a grouping of a set of blobs. The container name is scoped by the account.
Blob – Blobs are stored in and scoped by Blob Containers. Each blob can be up to 50GB. A blob has a unique string name within the container. Blobs can have metadata associated with them, which are
pairs, and they are up to 8KB in size per blob. The blob metadata can be gotten and set separately from the blob data bits