Hair transplant or Hair restoration is a type of surgical procedure which uses your own hairs that are transplanted in the bald areas or areas with decreased hair density. So these hairs are very much natural, they grow like normal hairs and you need to trim them when they grow.
Hair transplant can be done by FUE (follicular unit extraction) or FUT (follicular unit transplantation) or combination of both. In FUE, punches are used to exract har follicles and in FUT, a strip of hair bearing scalp is taken and then hair follicles are separated from it. Every technique has its pros and cons.