The scale allows you to choose from four font sizes for windows. You can change the default so that all applications subsequently open in the size you specify. Note that when you scale the font, the window scales with it.
You can choose from these four sizes:
small
medium (the default)
large
extra large
Not all fonts styles and sizes appear on the screen satisfactorily. If the size is too large, some items, such as menu buttons, may be obscured.