This article contains a review of relevant research concerning the implementation and operation of a professional learning community (PLC). The term "PLC Lite" is defined as the ineffective operation of a team acting under the umbrella of a PLC. Although many schools operate under the term PLC, daily operations do not produce evidence of implementation of a true PLC model. In order to help schools, avoid PLC Lite, the article explains the foundational structure of a PLC and discusses the four essential questions for true implementation to ensure that all students learn at high levels.