GLYPHICONS is a library of monochromatic icons and symbols that are very frequently used within toolbars and other navigations menus in the web applications. Glyphicons icons and symbols are nothing but a font and the actual name of the font is Glyphicons Halflings that are not free and require licensing, However it comes free along with Bootstrap download.
Generally, when we download Bootstrap from http://getbootstrap.com website, it contains a fonts folder that contains necessary fonts for different format.