Mac OS X has multiple Fonts folders to organize the fonts on your computer. Where you install a font determines when and who can access it. Mac OS X has at least four Fonts folders, depending on software installation and number of users. This article will distinguish the essential folders and fonts for you.
Installing Fonts
Many fonts will be installed by the Mac OS X Installer and other applications. You can also install fonts by copying or dragging font files to any of the standard Fonts folders in Mac OS X, including your User Font folder.
Font Security and Usage
The various Fonts folders follow the overall Mac OS X security design. The folder in which a font is located determines who can access and use the font.
Font files for use on an individual computer are set apart from those for use on a network. Additionally, on an individual computer, system software files are set apart from those under the control of a user or Admin user.
So for example: If a user installs a new font at ~/Library/Fonts/, the font is available only to that user. If a root or Admin user installs the same font at /Network/Library/Fonts/, all network users can use the fonts (assuming that the network is set up for sharing).
Font Activation
Changes to Fonts take effect when an application is opened, a user logs into the account or computer, or some font management software activates it. Duplicate fonts are resolved based on the order of precedence defined for the standard Fonts folders from highest to lowest priority shown below.
Font Folders and Locations
User (~/Library/Fonts/ - the tilde character (~) represents a user's Home, which may be local or remote)
Each user has complete control over the fonts installed in their Home. These fonts are available to that user when they are logged into the computer. Fonts installed here are not available to all...
Read more Essential Fonts and Folders for Mac OS X at PrepressX.