The nurses can fill various roles from the bedside clinicians, nurse educators, nurse managers, until nurse practitioners. The job of the nurses now is not only to treat the sick patients.
If you become this nurse, you will work in the various fields like the adult, pediatric, and even the neonatal nursing practice. You will find the nurses in the area with critically ill patients such as in the intensive care units (ICU), pediatric ICUs, the cardiac catheter, telemetry units, progressive care units, emergency departments, etc.
There will be a critical-care training course that you must take before you become a critical care nurse. The training course will provide you the information and the knowledge you need to treat the critical patients. It is even better if you take the certification since some employers prefer to hire the certified nurses. The certification refers to the higher level of knowledge and has more specialty practice experience.
Related to the job, the nurses are educated with the knowledge beyond their basic education as the RN or the Registered Nurse. The advanced knowledge is a must since they face the critically ill patient and the family's member which have more needs than ordinary patients.
As it stated above, before you can be the nurse, you must be a RN or Registered Nurse. However, the requirement is different from country to country. You can see the student's exposure in many nursing schools. Becoming a RN, it means you will need to get BSN or Bachelor Degree in Nursing and pass the exam for the national license.