The content of the blog system was usually stored in a database and stored in different types. The following are some common types: Relational database: Relational database is the most commonly used storage method for blog systems. It uses tables to store the content of the posts. Each table contains a primary key and one or more foreign keys to associate different posts and content. Relational database can provide efficient query and data retrieving functions, but it usually requires a more complex programming model to process large amounts of data. 2. Non-Relational Data Base: Non-Relational Data Base (Nosql) usually doesn't use tables to store data, but instead uses structures such as key-value pairs, documents, or column families. This structure could better adapt to large-scale data and complex query requirements. Some of the more popular Nosql libraries include MongoDB, Cassandra, and Redis. 3. Filesystems: Some blog systems store content in local files. This method allows users to freely upload and share files, but requires additional configuration and management to deal with file access and permission issues. Regardless of which type of blog system you choose, it will usually use a database to store the content of the blog posts for efficient, reliable, and easy to manage data storage and query.