ESP teaching began to emerge because general English was not always helpful in real-life professional situations. ESP focuses on the specific language needs of students' fields by tailoring materials to their professions and tailoring skills, structures, functions and vocabulary to what students will need for working environments. When selecting materials, teachers should consider students' needs, interests, and proficiency levels as well as the flexibility to adapt materials for different groups. Tailor-made electronic materials allow for greater independence, choice, and flexibility in learning while published materials provide established structure. Evaluation of materials helps improve their quality and suitability for target learners.