Endoscopy is the technique of using a tube with a lens and a light source to look into a body cavity through a small opening. An endoscope is like a small camera that looks at the pathology or problem. The endoscope has a light source and is connected to a monitor. The surgery is performed while looking at the screen and actual target size is magnified more than a 100 times. This approach parallels the advance from open abdominal surgery to laparoscopic surgery. The purpose is to get to the target pathology or problem while minimizing the trauma to the surrounding tissues. This approach can be used to treat both brain and spine disease in neurosurgery.