The Leukemia & Lymphoma Society explains it best:
"Lymphoma is a general term for a group of blood cancers that originate in the lymphatic system. The lymphomas are divided into two major categories: Hodgkin lymphoma and all other lymphomas, called non-Hodgkin lymphoma (NHL)."
From the MedlinePlus Medical Encyclopedia:
"lymph-" refers to the lymphatic system, part of the immune system
"-oma" refers to "tumor"
About 11% of lymphomas are Hodgkin lymphoma, and the remaining are NHL.
The differences between the two lymphomas:
- "Hodgkin lymphoma is distinguished from other types of lymphoma by the presence of the Reed-Sternberg cell."
- NHL has many different types of diseases under this "umbrella term". Typically, lymphomas (including NHL) occur from a change in the white blood cells.
Does this help? Please write back if you would like more information, as I did not want to give you an information-overload!