EDLG is a free German language course which teaches you German through conversation on various topics. You can find the website here: http://www.hueber.de/.
A bachelor’s degree is called “Bachelor of Arts” (Literature, History, Language, Music, Art, etc.) or “Bachelor of Science” (Physics, Biology, Chemistry, Mathematics, etc.). The suffix “-Edlg” before the degree is something like “Master’s degree”, because “Edlg” is the abbreviation of “Eidgenössisch Diplom” (Federal Diploma).
EDLG is a 4 year German course for highschool students. The starting age is between 14-16. The course is given at the Goethe Institute. There are also two types of 2 year courses for non high school students, but these are less common. More information about courses can be found here: http://www.goethe.de/
Edlg is the German abbreviation for “Erzieherische Leitung” which translates to “Educational Leadership”. The grades can be translated as follows: Edlg 1 = Grundschulgruppenleitung (Group Leader for elementary school); Edlg 2 = Grundschulleitung (Elementary School Principal); Edlg 3 = Sekundarschul-Grundschulleitung (Secondary School-Elementary School Principal); Edlg 4 = Sekundarschulleitung (Secondary School Principal).
Edlg is short for Elektronischer Doppelsteuerabzug, which means electronic double-taxation offset. It is a tax system for tax-free and tax-reduced rates for spending money on personal (i.e. non-business and non-professional) items like food, drinks, and similar things. To understand it fully, it is useful to know that the German VAT tax Details.