I'm an LPC, a Licensed Professional Counselor. This means I'm licensed to work as a counselor, who counsels (listens and offers direction) in a skillful, professional way. It also means that I can call myself a psychotherapist, a clinician who works within the psyche -- a mental health therapist, who, like a physical therapist or massage therapist, offers relief by helping to move and strengthen various parts. Instead of working with muscles and tissue, for example, I work with thoughts and emotions.
I'm also a LMFT, Licensed Marriage and Family Therapist. This means I'm licensed to work with close relationships; I have extensive specific training in building and maintaining healthy relational skills. In this realm I still work with thoughts and emotions, but additionally with safely communicating them. Being an LMFT also means I can call myself a psychotherapist. Another common set of initials for a psychotherapist is LCSW, a Licensed Clinical Social Worker. LCSW's are especially trained to connect people with resources in community.