Explanation:

Section 62 of Evidence Act – 
62. Primary evidence. –– Primary evidence means the document itself produced for the inspection of the Court. Explanation 1. ––Where a document is executed in several parts, each part is primary evidence of the document. Where a document is executed in counterpart, each counterpart being executed by one or some of the parties only, each counterpart is primary evidence as against the parties executing it. Explanation 2. –– Where a number of documents are all made by one uniform process, as in the case of printing, lithography or photography, each is primary evidence of the contents of the rest; but, where they are all copies of a common original, they are not primary evidence of the contents of the original.