i am in 11th class
Bacteria is a cellular structure. That means it is composed of a cell. Cell is a structure that contain cell membrane. Inside the cell membrane there is a cytoplasm and genetic material like DNA. Bacteria can reproduce by its own. It doesn't require anyother cell for reproduction.
Virus is acellular. Means it is not cell. It is only a genetic material (either DNA or RNA) surrounded by protein. It doesn't have cytoplasm or cell membrane. It reproduce with in another cell that is called host cell. Without host cell virus can't reproduce.