The Problem
As you probably know, Salesforce releases new versions of its software on a regular basis. New releases enable new features in the orgs and sometimes you just need those features to deliver your project.
The information about the org version is not included in the Company Information section of your SF org. There are a few steps needed to get this information.
The Solution
Open in your browser the below URL:
https://status.salesforce.com/instances/<YourInstanceHere>
where <YourInstanceHere> is your Org instance name, for example EU31, AP9, DB796 or any other instance. Like the one below:
https://status.salesforce.com/instances/AP20
Once you open the URL, the information about the Org version can be found on the right hand side of the screen:

There are some other information on that screen as well:
- overall system status
- specific service status (Core Service, Analytics, CPQ and Billing, etc)
- Region, where the server is located
- Products available on that instance
You can also open the History Tab to see how was the service recently, and check all the planned and scheduled Maintenance of your instance (for example to learn when the new version will be installed on your instance).
More information on that subject can be found here.