The other difference is with their teeth. Alligators have a wider upper jaw than lower jaw so when their mouth is closed the teeth in the lower jaw are almost completely hidden and fit into sockets of the upper jaw. In crocodiles, the upper and lower jaw are the same width and so teeth in the lower jaw fit outside when the mouth is closed. This makes them look like they have interlocking teeth. Another difference is the skin of a crocodile which is covered in sensory pits, whereas alligators only have these pits near their jaws.
Some crocodiles are more aggressive than alligators.
There are probably more incidents of humans being attacked by crocodiles than alligators because there are more crocodiles in existence. Their diet is diverse. They prey on anything from dragonflies and bats to sharks, antelopes and even buffalo. Although attacks on humans have occurred, most species of crocodilian don't include humans as a food source. In fact, it has been suggested that a person bending down over a water source may resemble an antelope in the eyes of a crocodile and this is why the attacks occur.