Answer:
On a biological level, the main difference is that bacteria are free-living cells that can live inside or outside a body, while viruses are a non-living collection of molecules that need a host to survive.
Don't drink it, Filter it first, then boil it for two minutes minimum to kill the bacteria.
They have different sizes and shapes. An example would be a tomato and a grape. Tomatoes are red, grapes are purple/green. Grapes are small, tomatoes (most of them) are large. This must be because the cells that make the tomatoes differ from the one that makes the grapes. Hope this helped/made sense :)