A simile is a figure of speech that directly compares two things through some connective, usually like, as, than, or a verb such as resembles.. A simile differs from a metaphor in that the latter compares two unlike things by saying that the one thing is the other thing.
A galaxy is an enormous collection of gas, dust and billions of stars held together by gravity. One galaxy can have hundreds of billions of stars and be as large as 200,000 light years across.
Alongside stars, the galaxy is the most important unit of organization in the entire universe. There are an estimated 100 billion galaxies in the visible universe, each with between about ten million and a trillion stars. The average galaxy includes about 10 71 atoms, and ten times more invisible mass in the form of dark matter.