3 Answers

what it means is.......if you have a degree or certiicate,or endorsement in ESL............then you can teach kids in the U.S. for whom English is not their first language. It's usually done as an adjunct to their regular class.  Or, you could teach English to foreign speaking adults.

ESL does mean English as a Second Language, and a boat load of federal funding!!

If I moved to Mexico would my kid be entitled to SSL?  I think not, again, we have to be everything to everybody.  Back through history, other of our good people who came here from other lands by the masses learned to immerse and intergrate into our culture, nothing less than when we travel to all of these other lands and cultures! 

Common abbreviation for ESL is English as a Second Language.
Other abbreviations can be found at
http://en.wikipedia.org/wiki/ESL_(disambiguation)