Although it is approximately 2,500,000 light-years The Andromeda Galaxy is the nearest spiral galaxy to our own (The milky way). A galaxy isn’t an individual object, its a group of stars,
Of the two types of galaxies we have the dwarf galaxies and the larger ones are called spiral which includes Andromeda, our own Milky way contains 200 billion stars Andromeda is massively bigger then the milky way and contains 1 trillion stars; 5 times as many stars as the Milky Way.There are even larger galaxies but we won’t go into that.
Andromeda was named after the princess Andromeda, from Greek mythology, the poor Princess was punished for her mothers bragging, she was chained to a rock to be sacrificed to a sea monster, don’t worry in the end she was saved by Perseus who later was to become her husband, and it is said, this story was later converted to the legend of St. George and the Dragon, anyway enough of this fantasy story back to Andromeda.
To find Andromeda first find the constellation of Ursa Major (Great Bear) in England we call it the plough in the states it called the big dipper Andromeda is the cloudy mass closed by.
There was even a film made in honour of Andromeda called the Andromeda Strain where a satellite returns to Earth containing a virus, killing a complete village, and just like The Greek Princess it had a happy ending.