TEFL is used when English is taught in a country where it is not the primary language. TESOL encompasses both TEFL and teaching English to nonnative speakers in a country where English is the native language. Although there are minor differences, TEFL and TESOL are accepted equally as English-teaching qualifications.
Students can acquire TEFL and TESOL certification through online courses. Advanced courses exist for those who wish to enhance their study beyond basic certification.
The world's first online TEFL course originated in Australia in 2001 with i-to-i, still active in the field. TEFL International was the first accredited organization to offer online TESOL certification, and since its inception, other accredited online TEFL and TESOL programs have flourished.
Online TEFL and TESOL courses range from 40-hour courses to 250-hour course sets. As of 2010, the prices for the online certification courses ranged from approximately $150 to $500.