English
The most common use is to replace the hyphen to make clear a strong joint between words or phrases, such as "the Ernest Hemingway/William Faulkner generation".
For a specialized use of the slash in the titles of fan fiction stories, see slash fiction.
Arithmetic
A solidus is used to separate the numerator and denominator in a vulgar fraction, or as a division operator in general.
- 3/8 – three eighths
- x = a / b – x equals a divided by b
Computing
Usually called a slash or sometimes, unnecessarily, a forward slash, / is used to separate directory or names in Unix file paths and in URLs.
- www.wikipedia.org/wiki/Solidus_%28punctuation%29
This is in contrast to the backslash \\ which is path delimiter on Microsoft Windows systems. Windows uses the backslash rather than the slash because in the early days of MS-DOS -- before directories were supported! -- the slash was chosen as the command-line option indicator:
- dir /w /ogn c:\\windows\\