According to Googles Manish Bhargava"many people are more comfortable formulating search queries in their own language but have difficulty typing these queries into Google."So thats why the virtual keyboard was created.

The on-screen keyword lets you type directly in your local language script no matter where you are or what computer youre using.

You will see this virtual keyboard if you use Google search in any of the supported languages. A keyboard icon will appear next to your search bar and when clicked will produce the keyboard.
You can find further details on the virtual keyboards in the Google help article here.

These keyboards have been integrated in Google search in 35 languages including Arabic, Bulgarian, Icelandic, Serbian, Thai and Russian.

If your language isnt supported yet, then submit your vote for it to Google here.