Reaction rules, listed below, react on selected events on the site. Each reaction rule may fire any number of <em>actions</em>, and may have any number of <em>conditions</em> that must be met for the actions to be executed. You can also set up <a href=":components">components</a> – stand-alone sets of Rules configuration that can be used in Rules and other parts of your site. See <a href=":documentation">the online documentation</a> for an introduction on how to use Rules.