Ratify, confirm are comparable when they mean to make something legally valid or operative.
Both terms presuppose previous action by a person or body with power of appointing, of legislating, or of framing such a document as a constitution, a treaty, or a contract, and imply reference therefore only to the act of the person or body endowed with the power to accept or to veto the appointment, bill, or document.
The terms are occasionally interchanged without loss, but ratify usually carries a stronger implication of approval than confirm and is therefore used by preference when the acceptance of something (as a constitution, a treaty, or a course of action) that has been framed or proposed by a committee or a small body is put up to a larger body (as a society, legislature, or nation) for a vote that testifies to its approval.
Confirm, on the other hand, stresses the giving of formal or decisive assent as necessary to a thing’s validity; it applies specifically to appointments made by an executive .(as a president or governor) that according to the constitution of a nation or state require the consent of a body (as a senate, a legislature, or a council) before they are definitely settled and made legally valid.