Sterile means that no bacteria are present. When we use sterile technique, we are trying to block bacteria from the patient. In this case you would be taught to wear gloves that are sterile so that you do not touch the catheter with your hands.
Sterilization is the process used to kill all the bacteria on a piece of equipment.
Intermittent catheterization is usually done at home using clean technique. However, you do need to sterilize your catheters in between each use. Thoroughly rinse the catheter with warm water. Make sure you rinse both the inside and outside surfaces of the catheter. Place the wet catheter in a resealable freezer bag and zip the bag shut.