What kills bacteria?

Antibiotics, soap: Antibiotics kill bacteria inside the body, but different ones kill different types of bacteria. Soap or alcohol hand gel kills most of them on the skin, alcohol and high temperatures (oven or flame) kill bacteria on surfaces.

Disinfectants, antiseptics: All disinfectants (used on inanimate object) and most antiseptics (used on humans) when used iin their appropriate way, will kill bacteria. Many, but not all antibiotics kill bacteria (bacteriocidal - penicillin is an example); some classes weaken bacteria, and require our immune system to finish them off. An example of this "bacteriostatic" effect is tetracycline.