Structured data
-Structured data is data that adheres to a fixed schema, so all of the data has the same fields or properties.
-Structured data is often stored in a database in which multiple tables can reference one another by using key values in a relational model.
Semi-structured data
-Semi-structured data is information that has some structure, but which allows for some variation between entity instances.
-while most customers may have an email address, some might have multiple email addresses, and some might have none at all
-semi-structured data is JavaScript Object Notation (JSON).
Unstructured data
-Not all data is structured or even semi-structured. For example, documents, images, audio and video data, and binary files might not have a specific structure. This kind of data is referred to as unstructured data.
Data stores
There are two broad categories of data store in common use:
Organizations typically store data in structured, semi-structured, or unstructured format to record details of entities
JSON - hierarchical document schema, good for both structured and semi-structured data., object-{} , collection - []
XML - tags, angle-brackets (<../>)
BLOB - mapped to printable characters ASCII or Unicode. binary include images, video, audio, and application-specific documents, Some file formats however, particularly for unstructured data, store the data as raw binary that must be interpreted by applications and rendered.
Optimized file formats