One of the major differences between psychologists and social workers can be noticed when you compare their professions, i.e., clinical psychology and social work. The major difference here is that social work is more like a general name as it also covers other fields; however, one of its types, i.e., clinical social work, is very similar to clinical psychology. Both professions are similar in some ways, most importantly, as they strive to help people solve their problems. However, a clinical psychologist is trained only with basic theories and principles from clinical psychology, whereas a social worker is trained to incorporate knowledge gained from psychology, political sciences, sociology, law, etc.
Part of the requirements to become a clinical psychologist is that you must possess a doctorate or a Ph.D., whereas a social worker is expected to possess a bachelor's degree or master's degree. Another difference is that social workers help people solve problems such as living conditions, jobs, medical care, housing, etc. but a clinical psychologist is more concerned with people with mental and emotional problems.