Microsoft offers three types of Azure storage in the form of Blobs( Binary Large Objects commonly known as files.). They are Block Blobs, Append blobs and Page blobs. Users need to specify the Azure blob storage type when they are creating storage space in the Azure cloud.
Once the blob has been created, its type cannot be changed and it can be updated only by using operations appropriate for that blob type i.e writing a block or list of blocks to a block blob, appending blocks to an append blob, and writing pages to a page blob.
Any blob type can be duplicated in a snapshot and can be leased for exclusive write access.
For more such details related to Azure Blob Storage click on the link of Microsoft