Pentagrams were used symbolically in Ancient Greece and Babylonia, and are used today as a symbol of faith by many neo-pagans, akin to the use of the Cross by Christians and the Star of David by Jews. The pentagram has magical associations, and many people who practice Neopagan faiths wear jewelry incorporating the symbol. Christians once commonly used the pentagram to represent the five wounds of Jesus.
The pentagram has associations with Freemasonry and is also utilized by other belief systems. A 'proper' pentagram, with its point directed upwards, represents the five elements of Earth, Wind, Fire and Water united in celebration of Spirit (pointing towards heaven). The inverted depiction of this (pointed down towards earth) symbolizes the opposite, a devotion of the elements towards worldly things, and causes many who practice other religions to associate the pentagram with evil forces.
A pentagram placed within a circle is called a Pentacle.