Both colds and the flu stem from viruses. However, cold viruses primarily cause respiratory symptoms. Colds rarely cause severe illness and usually do not require professional care.

The influenza virus is more serious than the common cold. While it has similar symptoms as a cold, flu symptoms more often include a fever, chills and body aches.

What exactly is the question? They are diseases caused by different types of viruses (Rhinovirus vs Inflenza). They also have, as you alreayd note, different symptoms associated with infection and different rates of severe problems.

What difference would you like to know more about?