The virtual keyboard is only of interest in case a touch screen is used without a connected real keyboard to the computer.
In case of a Raspberry Pi solution this is a common situation.
Some text fields can be edit by the virtual keyboard In dialogs which feature the [ABC] button.
The shift key is the on the bottom left with a [ ^ ] sign.
The new text will be used in case the [Enter] button is clicked.
With the [DE] button can be changed between the international and german layout.
To install a system wide virtual keyboard just install the following package:
sudo apt-get install matchbox-keyboard
Go to Start , then select Settings > Ease of Access > Keyboard, and then move the slider under On-Screen Keyboard.
A keyboard appears on the screen that can be used to move around the screen and enter text. The keyboard will remain on the screen until you close it.
This virtual keyboard can also be used with Rocview, but its an external dialog which must be on screen and reachable to be of any use.
The Rocview integrated keyboard is preferable.
Tip: Highly recommended for administration tasks. (Without a real keyboard connected.)