Groups of bright stars that appear close together in the sky are called constellations. They form patterns that never seem to change over hundreds or even thousands of years. The sky is divided up into 88 constellations.
Many of the constellations were named by ancient astronomers after things they thought the star patterns looked like—for example, a lion (Leo) or a swan (Cygnus), or a character who featured in their myths, such as the hero Hercules.
The stars seem to be close together because they are in the same direction in space from Earth, but each star may lie 10 or 1,000 light-years away from us.
If you live on the equator, you will be able to see all the constellations at some time during the year. If you live north or south of the equator, there are some stars around the opposite pole that you will never be able to see—they will always be below your horizon.