Because every style (except a Default style) inherits the settings from its parent, you need to set only the values that are different from the style’s parent. There are dozens of settings for character and paragraph styles, and you don’t want to keep track of every setting for every style.
Every setting for a style has a checkbox where you indicate whether the setting is active for the style. If a setting is inactive, the style inherits the setting from its parent (or its parent’s parent, and so on). If a setting is active, the style applies the setting.
Default styles contain a value for every setting. If you look at a default style in the Styles Editor, you will see that every setting has a check mark. The check marks are disabled, indicating that you cannot disable a setting for a Default style. (There is one exception to that rule: the Apply Styles settings for paragraph styles are enabled for the Default paragraph style.)
You can change any setting for a Default style just by setting the desired value. For other styles, you must enable a setting by checking its box before you can set its value.
In the picture below, a character style’s font and font size settings are active, and its color settings are inactive.
The check boxes make it easy to see what settings a style will apply.
To activate a setting for a style: