A logic model, also called a conceptual model and theory-of-change model, is a visual representation of how a program is expected to "work." It relates resources, activities, and the intended changes or impacts that a program is expected to create. Typically, logic models are diagrams or flow charts with illustrations, text, and arrows that indicate how planned work is expected to benefit program participants. Logic models describe the cause-and-effect processes through which an intervention is expected to work and how these activities flow together to achieve program outcomes. This brief describes the key components of a logic model, identifies why logic models are useful, discusses different types of logic models, the formats that they take, and the resources available to programs for creating them. The brief concludes with an "In the Spotlight" on the Entering the College Zone (ECZ) program, located in Greensboro, North Carolina. (Contains 1 figure and 3 endnotes.)