Is there a grade difference between patent claims 2 and 3?

Patent claims can only be divided into independent claims and dependent claims, and dependent claims can only refer to the previous claims.

However, if claim 3 mentioned in LZ refers to claim 2, claim 3 can further define the scope of protection.

For example:

1. A XX device (method) includes A, B and C, and is characterized by also including D. ..

The protection scope of this independent claim is: a+b+c+d.

2. The XX device (method) according to claim 1, further comprising e. ..

The protection scope of this dependent claim: A+B+C+D+E.

3. The XX device according to claim 1 or 2, further comprising F. ..

Scope of protection of dependent claims:

A+B+C+D+F or A+B+C+D+E+F.

In this case, claim 1 is an independent claim, and claims 2 and 3 are subordinate claims. The scope of protection of claim 3 further defines claim 1 and claim 2.