In our subject of study, TESOL stands for Teaching English to Speakers of Other Languages and includes what used to be called TEFL (Teaching English as a Foreign Language) and TESL (Teaching English as a Second Language).
Generally, TEFL emphasises aspects of teaching English in countries where English is not extensively used in daily life, such as Russia, China, France and Brazil.
The term TESL focuses on the needs of learners who will use English in their daily lives, in addition to their mother-tongue. In many countries, such as Zambia and India for example, English is used as an official language in government, in business, in newspapers, TV and radio as well as being the main medium of educational instruction in schools and colleges, as well as universities.
The acronym TESOL include both TESL and TEFL and is used around the world.
The best teachers of English around the world when they are TESOL, TEFL or TESL-qualified, adapt their teaching methods, their expectations of students, their teaching materials and their classroom activities to their local environment and the specific needs of their learners.