A walk through of the available Customize features
Using Customize for visual edits
Publishing your customisations
The Customize Screen is a live preview editor that lets you see the visual impact a change will have on your site–before making it go live.
Depending on what features are integrated with your site’s current active theme, Customize provides tools for visually editing or removing the title and tagline, uploading and cropping header images, changing the background color or setting a background image, toggling custom menus, adjusting display settings and managing widgets.