ELT, or English Language Teaching, is an encompassing term utilized in the teaching and learning of English as a foreign language. In its essence, the abbreviation marks any form of instruction that revolves around mastering the English language. Synonyms of ELT often include EFL (English as a Foreign Language), ESL (English as a Second Language), TEFL (Teaching English as a Foreign Language) and TESOL (Teaching English to Speakers of Other Languages). All of these synonyms work to provide reference to the same discipline, differing in terminology depending on the context and the nature of the course being taught. Ultimately, they denote teaching approaches, curricular resources, and assessment techniques that correspond to each individual learner's proficiency level.