What is the DSM-5?
The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (2013). This is put out by the American Psychiatric Association and contains the most up-to-date diagnostic criteria for various disorders and conditions, including Autism Spectrum Disorder (ASD).
The DSM-5-TR (Text Revision) (2022) contains a slightly revised description of Autism Spectrum Disorder (ASD).