Some fonts are also available as <emphasis>variable</emphasis> font files.Unlike a normal font file which only contains one variation, a variable font file contains infinite variations.Each variation can be defined by the application using this font by assigning number(s) to one or more variables.There are also pre-defined <emphasis>named instances</emphasis> analogous to the traditional variations.For example, with the variable version of Noto Sans, the weight variable can be assigned any number not less than 100 and not greater than 900, and 9 named instances are pre-defined: ExtraLight for weight=100, Regular for weight=400, Bold for weight=700, etc.So once a variable font file for Noto Sans is installed, all the 9 named instances (or <quote>variations</quote>) are available.Note that the slope is not defined as a variable in the variable version of Noto Sans, so Regular and Italic are still traditional variations and a separate variable font file is needed for the Italic variation.