The authentication plugins operate when users login to your site or administrator. The Joomla! authentication plugin is in operation by default but you can enable Gmail or LDAP or install a plugin for a different system. An example is included that may be used to create a new authentication plugin.
Editors are used thoughout Joomla! where content is created. TinyMCE is the default choice in most locations although CodeMirror is used in the template manager. No Editor provides a text box for html content.
The search component uses plugins to control which parts of your Joomla! site are searched. You may choose to turn off some areas to improve performance or for other reasons. Many third party Joomla! extensions have search plugins that extend where search takes place.