This book introduces fundamental psychotherapy and counseling theories. The basic concepts of theoretical foundations within a general framework are first introduced, and then the treatment theories and principles are covered. This book uniquely separates the principles, mechanisms, and techniques, and, with distinguishing theoretical and practical discussions, it seems that the students can find out how to link theory and practice in psychotherapy and counseling. Strengthening theoretical bases in short and teaching practical orientation in detail raises the student's willingness to put the principles in action. How to prepare the therapist and authorities for a successful treatment or counseling is briefly outlined in each theory. Critical review, evaluation, and empirical support, as well as the possibility of cultural adaptation in each theory make the students briefly familiar with the conservative application of the techniques and provide the grounds for their creativity to localize these techniques.