The main subject areas of cloud data include:

1. Cloud Storage: This refers to the various options available for storing data on the cloud, such as object storage, block storage, and file storage.
2. Cloud Databases: This covers the various options for storing structured and unstructured data on the cloud, such as relational databases, NoSQL databases, and NewSQL databases.
3. Cloud Data Warehousing: This deals with the process of collecting, storing, and analyzing large amounts of data on the cloud, often used for business intelligence and analytics.
4. Cloud Backup and Disaster Recovery: This addresses the various options for backing up and recovering data on the cloud, including the use of cloud-based backup services and disaster recovery solutions.
5. Cloud Data Management: This concerns the management of data on the cloud, including data governance, data quality, data integration, and data security.
6. Cloud-Native Data Processing and Analytics: This involves using cloud services and technologies to process, analyze and gain insights from large and complex data sets, such as big data and machine learning.