COVID-19 is caused by a germ (virus) that can make the body sick. People who have COVID-19 may have a cough, fever and trouble taking deep breaths. But some people, especially kids, who have the virus may not feel sick at all or may have mild symptoms such as those of a cold.

The boy in blue has Covid-19, the girl in purple does not.

If both stand close together and neither has a mask, there is a very high chance the girl will become infected if the boy coughs.

Even if the girl wears a mask, there is still a high chance she will get infected if she is close to the boy and he coughs.

If the boy wears a mask and coughs, there is still a medium chance she will get infected if she does not wear a mask.

If both the girl and the boy wear masks, there is a low chance of the girl getting infected even if he coughs.

If both the boy and the girl wear masks, and they stand at least 6 feet away, there is an even lower chance she will get sick even if he coughs.

Most commonly, the virus that causes COVID-19 enters people’s bodies when it’s on their hands and they touch their mouths, noses or eyes. A virus is so tiny that you can’t see it. This is why it’s important to wash your hands often and try not to touch your mouth, nose or eyes. If someone who has the infection coughs or sneezes on you from a close distance — closer than six feet — then that also can spread the virus.