The virgule (/), is known by many names, including diagonal, solidus, oblique, slant, slash, forward slash, and slash mark. The virgule is used to represent a word that is not written out or to separate or set off certain adjacent elements of text.
A virgule most commonly signifies alternatives. In certain contexts it represents the word or.
A virgule represents the word per or to when used with units of measure or when used to indicate the terms of a ratio.
14 gm/100 cc
a 50/50 split
A virgule replaces the word and in some compound terms.
in the May/June issue
A virgule punctuates some abbreviations and in lieu of a period.
Source: Grammar Done Right!