Abbreviations are of the utmost importance in the English language. The shorter versions of words enable us to easily communicate in a fast and clear way. However, not all abbreviations are obvious.
There are a lot of abbreviations taken from other languages like French. Other abbreviations aren’t even thought of as abbreviations anymore. Think of NATO or LED for example.
Abbreviationking.com has a broad overview of different, widely used abbreviations in the English language.