What is non-Hodgkin's lymphoma that has affected actress Jane Fonda?

Actress Jane Fonda has shared that she has been diagnosed with non-Hodgkin lymphoma. Non-Hodgkin lymphoma is a type of cancer that forms in the lymph system. It begins when a type of white blood cell, called a T cell or B cell, becomes abnormal. The signs and symptoms include swollen lymph nodes, fever, drenching night sweats, weight loss and fatigue.