This document discusses English for Specific Purposes (ESP). It defines ESP as an approach to language teaching where the content and aims of the course are based on the specific needs of the learners. The document traces the evolution of ESP from the 1960s and discusses some of the main researchers in the field, including Hutchinson and Waters. It outlines different theories of learning through ESP, such as behaviorism and mentalism, as well as approaches to ESP courses like language-centered, skills-centered, and learning-centered. Finally, it provides an example ESP lesson plan for electrical engineering students focused on vocabulary and graphic organizers.