Sent - Number of Karats your have sent to others
Received - Number of Karats others have sent you
Earned - Number of Karats you have earned from completing Golden Opportunities, Reflections, and encouraging others to complete Opportunities.
Lifetime - Total number of Karats you have earned and received (all time)
Current - Number of Lifetime Karats minus number of Sent Karats. Think of this as a balance, it is the number of Karats you have left to send to others. Current Karats are also used for drawings - whenever a drawing closes (countdown reaches zero), the number of Current Karats you have at that time will be the number of entries you have into that drawing.
*Note this feature is only currently available on the iOS mobile app 3.0.