The term "English Language Learners" refers to students whose first language is not English. This designation includes both students who are just beginning to learn English and those who have already developed considerable proficiency. ELLs are a complex group of students, with diverse gifts, educational needs, backgrounds, languages and goals. some ELL students come from homes in which no English is spoken, while some come from homes where only English is spoken; others have been exposed to or use multiple languages. 

Within the ELL program, there are several terms used to describe students of various levels of English language proficiency. 

ESL (English as a Second Language): Term formerly used to designate ELL students; this term increasingly refers to a program of instruction designed to support the ELL. It is still used to refer to multilingual students in higher education.

LEP (Limited English Proficient): Term used by the U.S. Department of Education to refer to ELLs who lack sufficient mastery of English to meet state standards and excel in an English language classroom. Increasingly, English Language Learner (ELL) is used to describe this population, because it highlights learning, rather than suggesting that non-native-English-speaking students are deficient.

EFL (English as a Foreign Language): nonnative-English speaking students who are learning English in a country where English is not the primary language.