From the introduction to Resolutions to Censure the President: Procedure and History (Feb. 1, 2018 R45087):
Censure is a reprimand adopted by one or both chambers of Congress against a Member of Congress, President, federal judge, or other government official. While Member censure is a disciplinary measure that is sanctioned by the Constitution (Article 1, Section 5), non-Member censure is not. Rather, it is a formal expression or “sense of” one or both houses of Congress. As such, censure resolutions targeting non-Members use a variety of statements to highlight conduct deemed by the resolutions’ sponsors to be inappropriate or unauthorized.
Resolutions that attempt to censure the President for abuse of power, ethics violations, or other behavior, are usually simple resolutions. These resolutions are not privileged for consideration in the House or Senate. They are, instead, considered under the regular parliamentary mechanisms used to process “sense of” legislation.