What is an ''assisted'' delivery?

Forceps or vacuum. While some obstetricians consider all deliveries attended by a provided (ob or midwife) to be "assisted, " this term technically applies to those deliveries requiring instrumentation to facilitate the delivery. This would involve the use of a vacuum device which provides traction by attaching to the fetal head with suction, or by use of forceps.
Forceps or vacuum. Sometimes the baby is very low in the vagina, close to coming out but for various reasons the mother is unable to push the baby out completely. In addition, the baby may be close to coming out but for various reasons the doctor might need to get the baby out immediately. In certain circumstances it may be easier, faster, and safer to use forceps or a vacuum to get the baby out.