English as a second language (ESL) is the use or study of English by speakers with different native languages. English is a language which has great reach and influence; it is taught all over the world under many circumstances. In English-speaking countries, English language teaching has essentially evolved in two broad directions: instruction for people who intend to live there and for those who do not. These divisions have grown firmer as the instructors of these two "industries" have used different terminology, followed distinct training qualifications, formed separate professional associations, and so on. Crucially, these two arms have very different funding structures, public in the former and private in the latter, and to some extent this influences the way schools are established and classes are held.