Wox has two kind of plugins, system plugins and user plugins.
System plugin are those plugins that Wox built-in, such as a calculator, color, the program searches. These plugins can not be uninstalled, but it can be disabled. In addition, the system plugin generally does not need a keyword triggering (except Web Search plugin)
User plugin are those plugins that written by other users, those plugin requires a action keyword trigger. For example, I want to use the translation plugin, then I need to use the 'yd + space + word' to fire. The action keyword can be configured.