TITLE: Why is it called a series?
QUESTION [13 upvotes]: Why did we make a new name for infinite sum?  Was something wrong with calling it an infinite sum, or is it highlighting a difference between finite and infinite?

REPLY [3 votes]: A series is a sum that results from adding up terms of a sequence (which has a well defined order). One should understand that mathematical concepts were viewed differently in the past - the notion of infinity, which we now take for granted, was not thrown around lightly, and notation also wasn't what it is now.
The same root as series (which is explained by @Mauro to come from Latin) is shared by all major romance languages I checked. In German, other Germanic languages, and most Slavic languages, the equivalent of the word order is used (and matches the word for order used for taxonomic rank in biology). In Slovenian, the word is vrsta, which loosely translates as queue/line-up (or possibly sort/species, but in this case the similarity with taxonimical classification is a coincidence).