'Her views on child development, which she expounded in 1927 in her first book, An Introduction to the Technique of Child Analysis , clashed with those of Melanie Klein...[who] was departing from the developmental schedule that Freud, and his analyst daughter, found most plausible'.  In particular, Anna Freud's belief that 'In children's analysis, the transference plays a different role... and the analyst not only "represents mother" but is still an original second mother in the life of the child'  became something of an orthodoxy over much of the psychoanalytic world.
Freud had numerous theories during his long career and life, but I will only remember a few of them. It is very well known that Freud did not like to be criticized. The most outstanding theory is about sexuality. If you haven’t read Freud before, you would be amazed at the emphasis on just the word “sex” alone. He sustained that people crave feeling to the skin: a hug or simply a kiss. Another important theory is about the id, the ego and the superego – related to the conscious and unconscious mind. He also investigated and stated theories for anxiety, Oedipal crisis, human sexual behavior, human conditions and basic therapy.