ESL is an acronym that is used primarily in educational settings and stands for English as a Second Language. It refers to teaching English to a person whose native or primary language is one other than English. Education laws in the United States require schools to provide ESL instruction in the classroom to any and all enrolled students whose primary language is not English.

The need for ESL programs to help U.S. students achieve educational proficiency standards in school is evident from the 2000 census, which found that close to 1 in 5 United States citizens spoke a language other than English at home. While this does not imply that those people do not also speak English, the census also found that roughly 10% spoke English either less than fluently or not at all. The primary language of these individuals was Spanish.

ESL programs in elementary and secondary school are advancing to meet the needs of the young people in the U.S. who need to learn English for proficiency success in school. ESL programs for adults are also advancing, but at a different rate and for different purposes. In public schools, ESL programs must meet certain state and federal requirements.

Many ESL programs for early childhood and elementary education focus on the English alphabet and phonetics through a combination of visual and auditory presentation. Computers in the classrooms play a large role in implementing ESL programs for students of all ages. ESL curriculum may vary from state to state, but all states are required to provide ESL learning programs within the guidelines of federal mandates for education, including No Child Left Behind. The Internet also provides valuable resources for ESL reinforcement, especially to parents of young children, as numerous sites provide printable worksheets and games that help reinforce English basics. Further, numerous ESL programs for adults are becoming widely available at community colleges and through distance learning programs.