1-What is the difference in application between identification& tracibility?

2- in d&d shall i mention only what the company is doing in design process ?
1. Interpretation may differ. You'll have to provide more details or decide for your own case.
For me, Identification means going on the floor and being able to show the auditor what a product/document/record is, what its purpose is and how we use it.
Traceability, for me, means being able to track a batch/lot from any point in our process. Often I've had to track a lot requested by the customer. If I can find records at each step of our processes and trace exactly what happened to this product, then I have traceability.
2. Your wording is somewhat unclear here, but haveing gone through our rough and tumble R&D process recently, I think I know what you mean.
Design and Development starts with a customer need/requirement, goes through the 3 steps you mentioned in your other post, and continues through manufacturing/construction all the way to customer feedback. It is, for us, much more than coming up with the blueprint.
I'm not clear on who your customer is. It is one thing I see missing in the information you provided so far.
With that said, you should include whatever you feel is necessary in
your QMS. The standard is fairly adamant on customer input and satisfaction.
Let me know if this helps.