TEFL (Teachers of English as a Foreign Language)
TEFL is an internationally accepted certification that a teacher has been properly qualified to teach English as a second language.  TEFL courses may be completed online or in a classroom.  Classroom courses are more expensive and extensive.  Typically a 60-120 hour online TEFL course should satisfy visa requirements. About 60 percent of provinces in China require a TEFL certificate to obtain a work visa.

Why do many governments and schools require TEFL certification?
Simply put, governments have a responsibility to ensure their citizens are properly educated.  Private schools have a responsibility to their students to provide a minimum standard of education.  TEFL is that minimum standard of certification for teachers.  Logically speaking, if you were the principal or headmaster of a school would you prefer qualified or unqualified teachers?  That is where most of the reputable schools require a minimum of a TEFL.

Many countries and schools require that a teacher have at least a TEFL certificate to obtain a teaching visa.  Teachers with TEFL certification may and rightly do expect higher salaries which TEFL certificate holders are eligible for.  Remember to remind schools that you are a TEFL graduate when negotiating your salary.  TEFL, per say, is the ineternational basic minimum standard that a teacher is prepared to teach.

What will TEFL teach me how to do?
TEFL is designed to make teachers efficient and effective.  TEFL teaches how to create and present lessons, where to find teaching resources, how to utilize audio/visual aids, how to manage students and classrooms, how to deal with difficult peer teachers and parents, generally the basics of most everything a teacher might encounter and familiarizing teachers with where the should look for the help and direction in the every day situations teachers may encounter.  Also...remember the TEFL providers, like ITTT, also have a network of schools and recruiters looking for teachers.

TEFL course costs start at about $200 for the basic 60 hour course, $500 for the 120 hour course and up to about $1,500 for the intensive in classroom courses.  

ITTT is one of the better known TEFL providers.  You can obtain a 10% discount on the cost of the course
by clicking this link.  https://www.teflcourse.net/apply/?cu=GOLDENdiscount

CELTA (Certificate in English Language Teaching to Adults)
CELTA is a more prestigious qualification and much more expensive and time consuming, costing upwards of $3,500 and requiring 1-2 months in classrom instruction and evaluation.