Taken from /core/includes/theme.inc (base Twig templates found in /core/modules/system/templates/, but can be overridden by chosen site Drupal theme).
'table' => ['variables' => ['header' => NULL, 'rows' => NULL, 'footer' => NULL, 'attributes' => [], 'caption' => NULL, 'colgroups' => [], 'sticky' => FALSE, 'responsive' => TRUE, 'empty' => ''],], 'item_list' => ['variables' => ['items' => [], 'title' => '', 'list_type' => 'ul', 'wrapper_attributes' => [], 'attributes' => [], 'empty' => NULL, 'context' => []],], 'image' => ['variables' => ['uri' => NULL, 'width' => NULL, 'height' => NULL, 'alt' => '', 'title' => NULL, 'attributes' => [], 'sizes' => NULL, 'srcset' => [], 'style_name' => NULL],], 'links' => ['variables' => ['links' => [], 'attributes' => ['class' => ['links']], 'heading' => [], 'set_active_class' => FALSE],], // From form.inc. 'input' => ['variables' => ['attributes' => [], 'children' => [],], 'select' => ['variables' => ['attributes' => [], 'options' => [],], 'radios' => ['variables' => ['attributes' => [], 'children' => [],], - Wrapper for a set of rendered radio buttons stored in 'children' 'checkboxes' => ['variables' => ['attributes' => [], 'children' => [],], - Wrapper for a set of rendered checkboxes stored in 'children' 'textarea' => ['variables' => ['wrapper_attributes' => [], ['attributes' => [], 'resizable' => "", 'required' => "", 'value' => "",], 'vertical_tabs' => ['variables' => ['attributes' => [], 'children' => [],], 'form' => ['variables' => ['attributes' => [], 'children' => [],], - Wrapper for a full form (provides the 'form' tag) 'form_element' - Wrapper for any form element. See /core/modules/system/templates/form-element.html.twig for details on variables 'fieldset' - Wrapper for a set of related fields. See /core/modules/system/templates/fieldset.html.twig for details on variables 'details' - Wrapper for a details component. See /core/modules/system/templates/details.html.twig for details on variables 'container' => ['variables' => ['attributes' => [], 'children' => [], 'has_parent' => "",],- General purpose theme for wrapping a set of children in a DIV element 'time' => ['variables' => ['timestamp' => NULL, 'text' => NULL, 'attributes' => []],], 'datetime_form' 'datetime_wrapper' 'dropbutton_wrapper' => ['variables' => ['children' => NULL],], // From pager.inc. 'pager' - Page navigation controls for paged content. See /core/modules/system/templates/pager.html.twig for details on variables // From menu.inc. 'menu' - Navigational menu. See /core/modules/system/templates/menu.html.twig for details on variables 'menu_local_tasks' - Local tasks menu. See /core/modules/system/templates/menu-local-tasks.html.twig for details on variables // From field system. 'field' - Default theme for displaying a field 'field_multiple_value_form' - Wrapper for editing a table of field items. See /core/modules/system/templates/field-multiple-value-form.html.twig // Themes for core Drupal page components. For reference only. 'html' - HTML wrapper for all pages 'page' - Content wrapper (defines all regions; usually overridden by Drupal site theme) 'page_title' => ['variables' => ['title' => NULL]], 'breadcrumb' => ['variables' => ['links' => []],], 'status_messages' => ['variables' => ['status_headings' => [], 'message_list' => NULL],], 'region' - Wrapper for an individual region on a page