What are These?
These are what people refer to as the zodiac signs. They originate as constellations which are groups of stars that form a identifiable shape which people can recognize. The 12 signs correspond to the time of year which is why people born during certain dates are a part of that zodiac sign group. For example someone born on October 19th would be a part of the Libra zodiac group and thus considered a Libra. Likewise every other day has a corresponding zodiac group. Each zodiac sign group has certain dates as to when people can be born into that certain zodiac sign group and usually is about a 30 day period.
Each zodiac group comes with different descriptions on how those people born into the groups act and behave. For the most part everyone that is born into a certain zodiac sign group will behave as intended according to their sign.