As often the answer is "it depends". Maybe the following discussion (even if it is centered around a different topic) might be helpful. It contains a number of definitions of the term "ontology" https://keet.wordpress.com/2017/01/20/on-that-shared-conceptualization-and-other-definitions-of-an-ontology/. All of them point into the direction that an ontology is just the "terminological part" of knoweldge representation (the T-Box).

There are other opinions around which consider even the assertional information (the instances of the concepts or in your terminology the data) about the represented world as ontology or belonging to an ontology (the A-Box), but often ontologies are just used to describe the terminology to represent parts of the worlds.

This makes sense, since different people/applications can share the same terminology to talk about their data or represent them in some common scheme.

As often the answer is "it depends". Maybe the following discussion (even if it is centered around a different topic) might be helpful. It contains a number of definitions of the term "ontology" https://keet.wordpress.com/2017/01/20/on-that-shared-conceptualization-and-other-definitions-of-an-ontology/. All of them point into the direction that an ontology is just the "terminological part" of knoweldge representation (the T-Box).

There are other opinions around which consider even the assertional information (the instances of the concepts or in your terminology the data) about the represented world as ontology or belonging to an ontology (the A-Box), but often ontologies are just used to describe the terminology to represent parts of the worlds.

This makes sense, since different people/applications can share the same terminology to talk about their data or represent them in some common scheme.

Thanks for your reply Thomas Hoppe made a 7 hour search and found out ontology mostly contain only the conceptualization of the domain according to this site:

http://www.cs.man.ac.uk/~stevensr/onto/node3.html

so at last i have to come up with an ontology and a knowledge base in order to continue my research. Again thanks a lot your reply helped

The abstract terms actually are described in the schema level. The detailed information is used to be described at the instance level. Thus, if I understand correctly your question you need to firstly find a way to create the schema with basic terms, and relationships. Then you need to map what you are called "real data" to instances (classes etc). I hope that you will find this answer useful.

Thanks Ioannis Chrysakis for your valuable answer