DSM stands for the Diagnostic Statistical Manual of Mental Disorders. The current version, as of September 2018, is version five. Psychiatrists, psychologists, and health care professionals use this manual as a guide to making professional diagnosis of mental, emotional, and behavioral illnesses.
Used by clinicians and researchers to diagnose and classify mental disorders, the criteria are concise and explicit, intended to facilitate an objective assessment of symptom presentations in a variety of clinical settings—inpatient, outpatient, partial hospital, consultation-liaison, clinical, private practice, and primary care. DSM consists of three major components: the diagnostic classification, the diagnostic criteria sets, and the descriptive text. 
The diagnostic classification is the official list of mental disorders recognized in DSM. Each diagnosis includes a diagnostic code, which is typically used by individual providers, institutions, and agencies for data collection and billing purposes.
Diagnostic Criteria sets
Each disorder listed in DSM has a set of diagnostic criteria. The diagnostic criteria includes symptoms that must be present, and other symptoms, disorders, and conditions that must be ruled out in order to qualify for a certain diagnosis. The DSM is intended for use by professionals in healthcare situations, not by the general public.
The third area of DSM is the descriptive text that accompanies each disorder. The text of DSM–5 provides information about each disorder under the following headings:
- Diagnostic Features
- Associated Features Supporting Diagnosis
- Subtypes and/or Specifiers
- Development and Course
- Risk and Prognostic Factors
- Diagnostic Measures
- Functional Consequences
- Culture-Related Diagnostic Issues
- Gender-Related Diagnostic Issues
- Differential Diagnosis
- Recording Procedures