Nursing encompasses autonomous and collaborative care of individuals of all ages, families, groups and communities, sick or well and in all settings. It includes the promotion of health, the prevention of illness, and the care of ill, disabled and dying people. Nurses play a critical role in health care and are often the unsung heroes in health care facilities and emergency response. They are often the first to detect health emergencies and work on the front lines of disease prevention and the delivery of primary health care, including promotion, prevention, treatment and rehabilitation.
RNs have a degree.

Nursing encompasses autonomous and collaborative care of individuals of all ages, families, groups and communities, sick or well and in all settings. It includes the promotion of health, the prevention of illness, and the care of ill, disabled and dying people. Nurses play a critical role in health care and are often the unsung heroes in health care facilities and emergency response. They are often the first to detect health emergencies and work on the front lines of disease prevention and the delivery of primary health care, including promotion, prevention, treatment and rehabilitation.
RPNs have a diploma in nursing.

Respiratory therapists (RTs) are healthcare professionals who assess, monitor and treat individuals with respiratory and cardio-respiratory disorders.
Respiratory therapists have the skills, knowledge and judgement to:

Maintain an open airway for trauma, intensive care, and surgery patients
Assist in cardiopulmonary resuscitation and support of critically ill patients
Provide life support for patients who can't breathe on their own
Attend high risk births and assist babies who have breathing problems
Stabilize high risk patients being moved by air or ground ambulance
Provide assistance in the delivery of general anaesthesia procedures
Administer inhaled drugs and medical gases such as asthma medication and oxygen
Conduct tests to measure lung function
Teach people how to manage their chronic lung disease or to quit smoking
Provide in-home respiratory care to adults and children

The PSW job description will always vary but in general, some of the common duties are:

Following the care plan, observing and reporting any substantial findings and/or changes in patient/resident/client’s behavior to the appropriate registered member of the healthcare team.
Working under the supervision of a Registered Healthcare Professional such as a Registered Nurse (RN) or a Registered Practical Nurse (RPN)
Performing tasks delegated to them (only if they are trained to perform the delegated task)
Assisting with ambulation, positioning and transferring using mechanical lifts such as a Hoyer lift.
Assisting or providing total personal care such as toileting, bathing and perineal care.
Assisting with eating, dressing and grooming.
Assisting nursing staff by answering call bells (In Hospitals and Long-Term care homes)
Performing sitter duty or patient watch for confused patients in clinical care settings.
Computer or paper documentation of Activities of Daily Living (ADL’s) and other findings.
Reporting behavioral and clinical changes to a Registered Nurse, Registered Practical Nurse, Resource Nurse or Manager.
Self actualization by helping patient/resident/client to reach maximum potential.