Forward slash vs. backslash
The forward slash / leans to the right. It is the one in web addresses (example.com/page), dates (10/01/2026), fractions (3/4), "per" (km/h) and pairs like and/or. Its formal name is solidus, and it is also called a stroke, an oblique or a virgule.
The backslash \ leans the other way. It is mainly a computer character: Windows uses it in file paths (C:\Users), and programming languages use it to escape characters (\n means a new line). Outside computing it has almost no use, so for a date, fraction or web address you want the forward slash.
Fraction slash, division slash and other special slashes
Unicode has several slashes for specific jobs. The fraction slash ⁄ is meant for building fractions, and some fonts use it to draw a proper fraction with small numbers. The division slash ∕ is the math operator for division, the big solidus ⧸ is a larger math slash, and the fullwidth ／ fits Chinese and Japanese text. The box-drawing diagonals ╱ ╲ ╳ join up without gaps, which makes them handy for text art and borders.
Look-alikes also help where the real slash is forbidden. Windows file names cannot contain / or \, so a name like "Q1∕Q2 report" uses the division slash instead. Keep the real slash in URLs and paths, where software must recognize it.
How to type a slash
On US keyboards, / shares a key with ? next to the right Shift key, the number pad has its own / key, and \ sits above Enter. With Alt codes, Alt + 47 types / and Alt + 92 types \. On phones, / is on the 123 keyboard and appears on the main keyboard when you type a web address.
In Discord, Slack and many games, a / at the start of a message runs a command such as /shrug. Writing fractions? The fraction symbols page has ready-made ½ ¾ ⅓ characters, and the division symbol page covers ÷.