What can be considered as structured data?

Structured data refers to information that is organized in a defined manner, typically in a format that is easily searchable and can be readily analyzed. Data stored in relational databases is the quintessential example of structured data. This type of data is stored in tables with predefined schemas that dictate the columns, data types, and relationships between tables. This inherent organization allows for efficient querying and data manipulation using structured query language (SQL).

In contrast, the other options represent forms of unstructured or semi-structured data. Emails and text documents, for example, contain rich textual information but lack a predefined format that structures that data in a consistent manner. Audio and video files also do not conform to a rigid structure, as the data is typically stored in formats that require specialized software for analysis. Similarly, social media interactions can vary widely in their format and content, making them difficult to analyze as structured data. Thus, the clear and organized nature of data within relational databases substantiates why it is classified as structured data.