When you activate a font, you make it available to the applications on your computer.
You can activate fonts temporarily, which means that they’ll be available until you restart your computer (or more technically, until you stop the Connect Fonts Type Core).
You can also activate fonts permanently, which means that they will remain available until you specifically deactivate them.
To activate a single font, select the activation style from the pop-up menu in the font tile.
To activate several fonts, select them and click the appropriate activation style button on the toolbar (cyan for Temporary, green for Permanent.)
To activate a set or library, select the set or library in the sidebar, click Select All in the font display on the right, then click a toolbar activation button.
When you activate fonts, each font’s entry will show a color bar (along the left in list view or across the bottom in tile view) to indicate its activation style (cyan for temporary or green for permanent)
To deactivate fonts, use the same process and choose Deactivate from the menu or click the gray Deactivate button.