Therapy refers to more in-depth work that involves exploration of possible causal factors in a person’s presenting complaints, working through potentially complex psychological issues, and processing difficult and personal information. Historically, therapy has tended to be longer-lasting than counseling, although that is no longer necessarily the case.
Counseling is usually used to refer more to shorter-term treatment which focuses on teaching skills, directing to community resources, and action-oriented behavioral change.
Therapy tends to go deeper and counseling lighter. Therapy tends to focus inward, while counseling focuses outward, i.e. changing things in the environment or training/teaching the client new behaviors to bring about changes in their lives. Therapy is generally more intensive, personal work that can bring about deeper, more lasting change.
I have done lots of both and believe that the best work done is integrative and holistic, utilizing both approaches as appropriate to the person, place and time.