Socialized medicine is what Britain has with the NHS. This is where government runs every health care entity, pretty much from the ground up.
No one in the USA is recommending this. No one wants it.
Nationalized health care is what most industrialized countries around the world have, what the Clintons wanted in the 1990's and what most plans are based on now. This system would allow you to keep your current health care provider, or pick any available. The only change is that you could also choose to use a government plan based on Medicare/Medicaid. It would give you the OPTION to choose the plan best suited for you.
The reason insurance companies do NOT want this system is because they currently take 25 cents of every dollar spent on health care as profits or for administration costs. Billions upon billions of dollars.
If these companies were forced to compete with Medicare/aid plans (which would also be an option to every American under nationalized healthcare), it would be tough on them, since Medicare operates on administration costs of 2 cents per dollar.....and they take no profit.
Drug companies and doctors oppose this system too, because they know if there is belt tightening....they are going to be asked to give up some money, in order to make the process cheaper.
It would force every part of the industry to either become very efficient (far cheaper) or die off.
How is this a bad system, unless you think profits for big insurance companies is the primary goal of our health care system?