HDFS is a Java-based file system that provides scalable and reliable data storage, and it was designed to span large clusters of commodity servers. HDFS has demonstrated production scalability of up to 200 PB of storage and a single cluster of 4500 servers, supporting close to a billion files and blocks.
Microsoft Azure Blob storage is a cloud computing PaaS that stores unstructured data in the cloud as objects/blobs. Blob storage can store any type of text or binary data, including documents, media files, and application installers.