What is the difference between hodgkin lymphoma and non-hodgkin lymphoma?

Both almost always. Begin in lymph nodes, and are composed of cells that appear to be variations of lymphocytes. Treatment and prognosis is quite different. The hodgkin's marker, the reed-sternberg cell almost always defines hd, and nhl dominantly is b-cell derived, but there are t-cell varaitions. Hd is not b cell in origin.
Disease type. The 2 diseases are closely linked. The hodgkin lymphoma was described by the doctor bearing its name and usually has a specific cell associated with it. This cell is not the target of new therapies for relapsed disease. In general terms, this disease is highly curable whereas some of the many types of non-hodgkin lymphoma are not.