Normally, a local anesthetic is given by injection through the skin near the base of the penis. During a circumcision, the foreskin is removed from the head of the penis (glans). Even though the person having the procedure will be awake, there will be no pain while it is being done. After the procedure, some discomfort is expected when the local anesthetic wears off. There are pain-killers that relieve any pain or discomfort.
For newborn babies, circumcision is easier and faster that it is with adolescents and adults. The healing period is much shorter for newborns and infants.