Linked data definition

The term "linked data" is used for both things: it's a set of principles, yes, but it's also common to refer to any data published using those principles as linked data.

A word of advice: don't get too hung up on dictionary definitions, it's far more important that you understand the concepts involved.

My own attempt at the dictionary definitions, so you can read about them and not have to worry about them afterwards:

• Linked Data: Data published under the Linked Data principles. Also, a community and research area built around the promotion and study of Linked Data and Linked Data principles.
• Linking Open Data (LOD): A W3C community project to promote and deploy Linked Data principles for datasets like DBpedia, etc. Started the LOD cloud (strictly speaking, the Linking Open Data cloud).
• Web of Data: An old phrase first used by Tim Berners-Lee in 1998 (lowercase in that instance). Refers to structured data on the Web that is linked. Definition varies from only including dereferenceable RDF documents linked on the Web, to also including other data formats such as Microformats, etc. that are linked.

These terms did not come about as rigorously defined terminology, and as such, people use the terms loosely ... the above definitions are probably not comprehensive in how people use those terms (e.g., LOD is now often used to refer to Linked Open Data: Linked Data with liberal licencing). As others have said, understanding the concepts is more important than understanding the definitions. If you understand the concepts, you can then pick up the intended meaning of such a term from the context of whatever is being said.

I'm not entirely clear on what you mean by "kind of data". (eg. qualitive vs quantitive, healthcare vs government etc. )

Regardless, I would call it a way /style / method / set of best practices for publishing data on the web. see - http://answers.semanticweb.com/questions/2127/historical-perspective-on-linked-data esp. http://tomheath.com/papers/bizer-heath-berners-lee-ijswis-linked-data.pdf

EDIT: and the resultant data is also referred to as linked data. I'm guessing thats what you meant by "kind of data". It is linked data by virtue of being published using linked data best practrices

but i'd certainly echo Jeen's advice on not getting too worried about the definitions etc.