If you own one share in a company X, you get one vote in the appointment of the company's management. That management may or may not give you some money called a "dividend" every year or so.I don't even know the difference between shareholders and bondholders.
Anyway: would such info be accessible if the banks were nationalised?
If you own a bond from company X, then they owe you money, and must pay you a set amount of interest every year for the duration of the bond. A bond and a loan are the same thing. When Ireland borrows money, it does it in the form of bonds. The interest is paid to whomever owns the bond, so a bond can be traded around from investor to investor. When somebody fails to pay the holder of the bond, he has defaulted.