1. The fact of being who or what a person or thing is.
1.1. The characteristics determining who or what a person or thing is.
1.2. [as modifier] (Of an object) serving to establish who the holder, owner, or wearer is by bearing their name and often other details such as a signature or photograph.
2. A close similarity or affinity.
3. [mathematics] (also identity operation) A transformation that leaves an object unchanged.
4. [mathematics] The equality of two expressions for all values of the quantities.
copied from online Oxford Dictionaries.
identity. concrete, parts from roses, copper wire, paint, scratched writing, photo of lines of hand.