A hernia occurs when something pooches out of where it is not supposed to be. Besides the inguinal hernia common ones are umbilical hernia where something pops out of the belly button and a hiatal hernia where stomach pops into the thoracic cavity through the diaphragm. I men the testes and spermatic cord are formed internally, and descend into scrotum The spermatic cord goes through an internal ring on the abdominal side through muscle layers and out the 'external ring' above and lateral to the base of the penis, and down into the scrotum. Hernias occur when weakness in the rings and wall allow the abdominal contents (fat or loops of bowel) protrude.
A direct hernia occurs when an internal ring area is weak and things pop out.
An indirect hernia slides along the spermatic cord out the external ring.
Examiner's target is the lower external ring and finding something sliding down. Examiner puts finger in upper scrotum to get loose skin, and pushes up following cord to the ring. Patient raises intra-abdominal pressure by coughing. Hernia if present is pushed onto examiner's finger.
Of note. Some med fet tales have examiner holding testes then asking patient to cough. As you can see from description of how it's really done, that the description is erroneous. Secondly I asked my doctor why I have to turn my head. "So you won't cough in my face." DUH.
The following link is photos of my second hernia surgery. I had a 'direct' hernia'
https://en.zity.biz/index.php?mx=gallery;ox=showalbum;ax=6062
The 'genitalia' part of the examination is the penis, scrotum and the contents--not just the testes. I had swollen veins of the spermatic cord, found and repaired at the same time I had my first hernia repair.