Cell Biology and molecular biology are two distinctly different fields of biology. 

Cell biology

• Is a field of biology that studies the behavior and cellular mechanisms of living cells in terms of their anatomy, morphology, and physiology
• Uses techniques such as microscopy and scanning to study prokaryotic and eukaryotic cells and cell functions
• Plays a crucial role in identifying morphological features and behavioral patterns in cells in response to environmental, metabolic, and chemical exposure

Molecular biology

• Is a field of biology that is based on the central dogma of life
• Uses techniques such as PCR (polymerase chain reaction), sequencing, and gel electrophoresis to study molecular level mechanisms such as understanding the relationship between DNA, RNA, and proteins
• Is an important diagnostic tool 
• Plays a crucial role in identifying and confirming most morphological and metabolic conditions