There's not really anything that describes the differences, considering they're not really comparable.
Gender conversion therapy is the same concept as gay conversion therapy. It is an attempt at changing what gender (or sexuality) a person thinks they are to conform to their society's or religion's expectations. It doesn't work and is harmful. https://en.wikipedia.org/wiki/Conversion_therapy
Gender affirming/confirming treatments are treatments that help make trans people less distressed about their bodies and relieve the symptoms of dysphoria. They exist under the umbrella of transgender health care. Treatments include hormones, surgery, and social acceptance among other things. https://en.wikipedia.org/wiki/Transgender_health_care