At one time, Latin was the official academic language in Europe. Until the early 18th century, the vast majority of all academic and scientific texts were written in Latin. This was primarily due to Latin's traditional status as a language for educated people, but also because the nature of the language allowed both accuracy and simplicity - the perfect language for explaining concepts both simple and complex.
As Latin's popularity faded, academics started to write in their native language instead, but since there were many set phrases in Latin that were both convenient and well-known, a few survived - usually in abbreviated form, like e.g. and i.e., which were covered in an older post. Most of these will probably be recognizable; but how many of the original forms did you know?
A.M. - ante meridiem - "before midday"
Cf. - confer - "compare"
C.V. - curriculum vitae - "course of life"
Etc. - et cetera - "and the others" (things)
Et al. - et alii - "and others" (people)
M.O. - modus operandi - "method of operating"
N.B. - nota bene - "note well" (or "please note")
Percent - per cent - "for every one hundred"
R.I.P - requiescat in pace - "may he/she rest in peace"
Vs. - versus - "against"
In older texts, etc. is sometimes abbreviated with an ampersand - &c - if you look at it carefully, the & symbol is nothing more than a slightly compressed "E" and "t" (et being the Latin word for "and").
It just goes to show that while Latin is considered a 'dead language', its influence can still be seen in our everyday lives.
This is just a small selection of Latin abbreviations still in use today - do you know any others?