ESP began in the mid-20th century to teach military personnel languages for their roles. It expanded to professional domains and is now characterized by needs analyses to identify skills needed in fields like aviation, medicine, and law. Materials are often authentic sources from those fields. ESP recognizes learners have limited time, prioritizing relevant content. Contemporary ESP addresses technological advancements, globalization, cross-cultural competence, English for Academic Purposes, hybrid learning models, and sustainability. It demonstrates flexibility and resilience through its dynamic development tailored to learners' needs.