English for Specific Purposes (ESP) focuses on meeting learners' specific language needs for their careers or fields of study. ESP emerged because general English was not always helpful in real-life professional contexts. ESP materials can be tailored textbooks or teacher-created materials that are relevant to learners' subject areas and needs. Tailor-made ESP materials provide purposeful learning opportunities and stimulate learners' curiosity about topics related to their lives and careers. ESP teachers evaluate and improve materials through pre-use, in-use, and post-use evaluation to ensure the materials best suit learners' needs.