Turn on/off Preview Panel
In the list of items, click three dots icon. Now, select Hide Preview Panel, if you want to turn off preview panel.
Or Show Preview Panel, if you want to turn it on.
If the preview panel is turned on, always when you click some item in the list, you will see side panel:
In the top part of the preview panel, you can click the icon for editing the item or for closing the panel.
In the General tab, you will see values of this item.
In the HUB tab you can see tasks, calendar events, journals, documents and emails order by date and time. If you click some item in the HUB, its detail will be opened.
HUB can contain a lot of items so you can use search field.