In tech circles, this is usually known as "unstructured data".
From Wikipedia, for example:
Unstructured data (or unstructured information) refers to information that either does not have a pre-defined data model or is not organized in a pre-defined manner.
Unstructured information is typically text-heavy, but may contain data such as dates, numbers, and facts as well. Examples of "unstructured data" may include books, journals, documents, metadata, health records, audio, video, analog data, images, files, and unstructured text such as the body of an e-mail message, Web page, or word-processor document.
Techniques such as data mining, Natural Language Processing (NLP), text analytics, and noisy-text analytics provide different methods to find patterns in, or otherwise interpret, this information.
Software that creates machine-processable structure exploits the linguistic, auditory, and visual structure inherent in all forms of human communication. Algorithms can infer this inherent structure from text, for instance, by examining word morphology, sentence syntax, and other small- and large-scale patterns.
While the main content being conveyed does not have a defined structure, it generally comes packaged in objects (e.g. in files or documents, ...) that themselves have structure and are thus a mix of structured and unstructured data, but collectively this is still referred to as "unstructured data". For example, an HTML web page is tagged, but HTML mark-up typically serves solely for rendering.