Hi,
This might make things clearer--
and
to expand on what temple1st said:
An RN can be Associates, Bachelors, or Diploma prepared.
Respectively the schooling in time is 2yrs, 4yrs, and 3 yrs.
The Diploma grad spends a great deal of time in the hospital (this has historically produced some of the real true nurses that have outstanding clinical and organizational skills). They graduate with a 'diploma'.
The Associates is a nurse who does not get the full liberal arts background that the Bachelors nurse receives. Much of the time the ADN is granted at a Junior or Communitiy College and the BSN at a University or 4 year college. Often the ADN is an older person (i.e., not fresh out of high school) and may be going 'back to school'. The first 2 years of the BSN are spent in the arts and sciences. The ADN is biology, anatomy, physiology, english, psych classes and then clinical. It is ususally more intense and the clinical may be held during off hours (saturdays or evenings).
You can go from your ADN to BSN through a bridge program. This generally takes 2 years fulltime.
There are a few programs where you can get a nursing degree in 1 year: they require a bachelors degree before hand and intense clinical (Yale has such a program).
Lastly, if i had to have my pick...(and i am a 4 year BSN with a Masters in Nursing) to staff a unit I would choose a mix of 2, 3 and 4 year grads. From my experience the work / clinical concentration is variable and each has its benefits. I also think they should streamline things and standardize the nursing programs. All Nurses sit for the same licensing exam.