Explain custom Menus Widget.

The Custom Menus Widget in WordPress allows you to display pages, categories, custom links, custom taxonomies, or post types in your sidebar or any widgetized area. Here's a step-by-step guide on how to use it:

1. Access the Widgets Area: Log in to your WordPress dashboard, go to 'Appearance' and then click on 'Widgets'.

2. Find the Custom Menus Widget: In the available widgets area, you'll find the 'Custom Menu' widget.

3. Add the Widget to Your Sidebar: Drag the 'Custom Menu' widget from the available widgets area to the sidebar or any widgetized area where you want it to appear.

4. Configure the Widget: Once you've added the widget to your sidebar, you can configure it. Give it a title and select a menu to display. If you haven't created a menu yet, you'll need to do that first under 'Appearance' > 'Menus'.

5. Save Your Changes: After you've configured the widget, click 'Save' to preserve your changes.

6. Check Your Site: Visit your site to see the custom menu in the sidebar.

Remember, the Custom Menus Widget is a great way to guide your visitors to specific content and make navigation easier on your site.