Which statement is correct about the nature of semistructured data?

Semistructured data is characterized by its variability in structure, which means it does not adhere to a strict, predefined schema like structured data does. This flexibility allows for different records to have different attributes or fields, making it possible to represent complex and dynamic data. Examples of semistructured data include JSON, XML, and NoSQL databases where the structure can evolve over time to accommodate different data types and requirements.

The other options highlight aspects that do not accurately represent semistructured data. For instance, a fixed format and easy queryability are traits of structured data, while semistructured data can indeed be queried but may require more complex querying methods than those used for data confined to rigid formats. Describing semistructured data as entirely unorganized and random does not capture its nature; while it is more flexible than structured data, there is still a certain level of organization present that allows it to be processed and analyzed effectively. Lastly, stating that semistructured data is only found in relational databases is incorrect, as this type of data often appears in various systems, including document stores and data lakes, which supports a more flexible schema.