The cystic duct from the gallbladder joins with the common hepatic duct to form the common bile duct.
From the en.wikipedia.org
The intrahepatic ducts eventually drain into the right and left hepatic ducts, which merge to form the common hepatic duct.
From the en.wikipedia.org
The neck tapers and connects to the biliary tree via the cystic duct, which then joins the common hepatic duct to become the common bile duct.
From the en.wikipedia.org
A cholangiocarcinoma occurring at the junction where the left and right hepatic ducts meet to form the common bile duct may be referred to eponymously as a Klatskin tumor.