The gallbladder is a muscular storage bag for bile, roughly the size of a small pear, which is attached to the liver, which is on the right side of your tummy, just behind your lower ribs.
A hernia occurs when the layers of muscle of the tummy wall split apart, leaving a gap through which the contents of the abdominal cavity protrude. This is what the lump or bulge is, at the site of your hernia.