The main difference between bacteria and a virus is that the viruses are smaller in size than bacteria and attach themselves to another living cell and use that cells' genetic material to reproduce themselves.
Also viruses cannot survive without a living host so they die if they don't have a living host.
Bacteria are living cells that reproduce independently without the need of a living host.
Also bacteria are prokaryotes and are unicellular microorganisms.
For bacterial infections to be killed you need the use of antibiotics which kills the bacterial infection making the infection go away.
With a virus such as the virus there's no cure and your body has to just work naturally to get rid of it.