Preview content before publishing
The preview mode for Umbraco is an incredibly useful tool for web editors. Shortly told it allows editors to see how content will look on various devices before actually publishing it. How it actually works is that it creates a cached version of the content, which can be previewed by the editor.
Why is the Umbraco preview function useful?
We are in 2016 so websites are browsed on many different devices, and there is a huge span between screen sizes. This means that you, hopefully, have a responsive website. To make sure that your content is optimized for all screen devices the editor/publisher have an opportunity to take advantage of the Umbraco preview function.
It allows the editor to click the preview button (see image above) in the content section before it is published. A new window will open with a cached version of the content and a left panel with buttons, which allows the editor to see content in a number of predefined screen sizes. It is possible to add or remove devices from the panel. Below is a couple of images that shows how it looks in mobile (landscape) and tablet (portrait) orientation.