When your part is finished printing, the printer runs a drying cycle. A timer on the LCD menu will count down the time remaining to dry the part. Drying the part gives it added strength, so you should not handle parts before they have adequately dried.
You can leave the part in the Build Bed after the drying cycle ends and it will continue to increase in strength. The longer a part is dried the stronger it becomes, although until it is infiltrated, it will still be fragile and should be handled with care.