Small lymphocytic lymphoma (SLL) is a type of non-Hodgkin lymphoma and is also known as chronic lymphocytic leukemia (CLL). SLL and CLL are the same disease, but the main difference is where the cancer cells are found:
SLL: Cancer cells are mainly found in the lymph nodes.
CLL: Cancer cells are mainly found in the blood and bone marrow.

National Cancer Institute
Definition of CLL/SLL - NCI Dictionary of Cancer Terms
CLL (chronic lymphocytic leukemia) and SLL (small lymphocytic lymphoma) are the same disease