A pretty nebula in the sword region of the constellation of Orion. It is 1,500 light years from Earth. An active star forming region, its stars have been formed in the past million years. It is visible with the naked eye as a fuzzy patch of light, noticeably different than a star. The trick is to not look directly at it. Through a telescope it is a lovely sight. The nebula is made visible by the radiation from some of the more massive stars it has spawned.
It is a popular research subject for astronomers looking to investigate how stars form and evolve in their early days because of its relative closeness to the Earth. A photograph of the nebula can be found in just about every astronomy book ever published.