Preferred Label
The default Preferred Label, or name, for all new concepts is "New Concept". To change the label, double click on the concept on the canvas, enter the new name, and hit the Return key. If the concept already had a preferred label you will be asked if you want to change the IRI to match the new label.
More information on the the IRI and naming conventions can be found here.
Note
Changes to the preferred label also appear in the Detailed Concept Information panel and the IRI.