Psychology is the science behind or the study of the mind and behavior. One of the main goals of applied psychology is to benefit society. A huge component of psychology is the drawing of commonalities, making generalizations, and identifying patterns in human behavior, including stimulus and response, environment and conditioning, as well as genetics. These, and many other components are brought together and examined, most often, for the purpose of behavioral change.
Counseling, as in, the practice of behavioral assessment through discussion, observation, treatment, and follow-up, is the easiest and most immediate method for bringing about behavioral change. An example can be drawn by comparing psychology to psychiatry. A psychiatrist might attempt to bring about emotional and behavioral stability by prescribing an anti-depressant, then following up to determine the drug's benefits versus its side effects.
A psychologist, or counselor, on the other hand, is going to treat the patient through one of several modes of behavioral therapy. Rather than providing a drug, a counselor provides ideas, highlights behavioral choices, and directs patients through a course of self-reflection as a method of improving mental health. In some cases, the end result for the the psychiatrist and the psychologist might be the same. However, without the counseling aspect, the psychologist would likely have no results at all.