aria-describedby
Identifies the element (or elements) that describes the object.
Relationship attributes indicate relationships or associations between elements which cannot be readily determined from the document structure.
Global states and properties are supported by all roles and by all base markup elements.
Description
Identifies the element (or elements) that describes the object. See related aria-labelledby.
The aria-labelledby attribute is similar to the aria-describedby in that both reference other elements to calculate a text alternative, but a label should be concise, where a description is intended to provide more verbose information.The element or elements referenced by the aria-describedby comprise the entire description. Include ID references to multiple elements if necessary, or enclose a set of elements (e.g., paragraphs) with the element referenced by the ID.
Example
Characteristics
Semantic HTML
Reference