Registered Nurse (RN): The 'specialized nurses' you talk of, and what this article is mainly about. Requires at least an associate's degree to be licensed, but increasingly an bachelor's is expected. Only they can administer any medication a doctor prescribes, and only they can assess your condition.

Licensed Practical Nurse (LPN): If they are certified they can also do blood draws. Requires graduation from an LPN program (usually about one year) to be licensed. They perform easily predicted tasks like a dressing change that do not require assessment. They can also administer some drugs based on the situation.

Unlicensed Assistive Personnel (UAP): In a big hospital, these are who are checking your temperature most of the time. They can only do basic tasks that do not require any medical training, even if their experience is larger than the RNs and LPNs they're under.

There are also many different technicians. In a big hospital, an RN acts as a middle manager delegating their work to these many different tiers. In an ICU, or in a small hospital, it will be done much more by themselves.