The tilde is a wavelike grapheme. It is used as a diacritical mark, as in the Spanish "tilded N" or eñe: Ñ. The tilde is also used in abbreviation, for example in dictionary definitions; as a symbol in mathematics and mathematical logic; and in programming and Internet addresses. The tilde key is near the top left of most United States keyboards. It is often used to switch between windows or toggle menus.
Locating the Tilde Key
Typically you will find the tilde key to the upper left of your keyboard, above the Tab key. To get the tilde character you will need to hold down the Shift key. On Macs, the key with the tilde is called the ` key. On British computer keyboards you may find the tilde key to the middle right of the keyboard, near the @ sign key.
Using The Tilde Key to Toggle
In some cases you can use the tilde key to toggle between applications, menus or windows, within an application. For example, if you are using Word on a Mac and have a number of documents open, you can hold the command and tilde keys down together to cycle through them. The tilde key has different functions depending on the application. In Excel, for instance, Ctrl and tilde together shows all formulas in cells.
The Tilde Key in Gaming
In some games, the tilde key has various uses including selecting groups of objects and bringing up or toggling between menus. In StarCraft, the tilde key selects all idle units. In some games, including Quake and Jedi Knight II, the tilde key plus shift brings up a console that allows the player to enter cheat codes.
The Tilde Key in Graphics Packages
In some graphics packages the tilde key can be used to cycle through windows. In Illustrator, holding down the tilde key while using one of the drawing tools will cause the shape to appear repeatedly as you move the mouse, making interesting geometric patterns. If you click and drag within an object with a pattern fill while holding the tilde key, the pattern fill will change. When creating computer graphics mathematically, the tilde may be used in notation.
URLs and Directories
The tilde symbol is used in some operating systems -- those based on or similar to Unix -- to denote the user's home directory. Similarly, a tilde in a URL may indicate a personal Web page housed on a Unix-based server. This can cause problems if you're using a keyboard without a tilde key; in this case, the character string %7e can be used in URLs in place of the tilde.