Create segments
  To create a segment you must use the CreateSegment method of PersonalizationManager.  First, you initialize the PersonalizationManager. When creating a new segment, it is recommended to set at least the following properties:
 
You can also set any other properties in this step - LastModified, IsActive, CriteriaGroups etc.
 
The following code creates a segment with the specified  Name and Description: 
  
The CreateSegment method has another overload that accepts an Id as a parameter. The following code demonstrates how to create a segment by Id: