the first thing you see is called the ASA.(air source adapter) This is what your tank screws into
The hose is called macro line or steel braided line(depending of if it's metal to plastic)
The next thing is the high pressure regulator. It regulates air down from the tanks output pressure. Most tiippmans have no need for a high pressure regulator, but it looks as if this one has has a electro-pneumatic solenoid added to it.
The yellow part is just another place where the high pressure regulator can be attatched. In this picture, it may be some sort of air chamber to keep shots more consistant.