The Tabs component introduces:

<%= code("render_tabs") %> accepts two key blocks, <%= code("tab_list") %> and <%= code("tab_panel") %>. Within <%= code("tab_list") %> call <%= code("tab") %> for each tab, accepting the text you want for the tab and making one of them <%= code("active: true") %> to determine the starting active state of the tab. Within <%= code("tab_panel") %> call <%= code("tab_panel") %> for each tab panel, accepting a block for the content of the panel and making one of them <%= code("active: true") %> to determine the starting active state of the panels (generally corresponding to the active tab).