"Systematic" refers to something that is done according to a fixed plan or system, often implying a methodical or organized approach. For example, a systematic review in research follows a structured protocol to gather and analyze data.
"Systemic," on the other hand, relates to a system as a whole, often particularly in the context of the effects or processes that affect an entire system, such as the body or an organization. For example, systemic issues in a company might refer to problems that affect the entire organization's functionality or culture.
In summary, "systematic" emphasizes method and order, while "systemic" focuses on the interconnectedness and holistic nature of a system.