Who is Examination-in-chief under Evidence Act?

Section 137 of the Indian Evidence Act, 1872 states that The examination of a witness by the party who calls him shall be called his examination-in-chief.

Cross-examination.—The examination of a witness by the adverse party shall be called his cross-examination.

Re-examination.—The examination of a witness, subsequent to the cross-examination by the party who called him, shall be called his re-examination. the cross-examination by the party who called him shall be called his re-examination.