Andromeda Galaxy is our neigbor, the closest major galaxy to Milky Way. It is one of the galaxies that is part of our Local Group cosmic neighborhood. It can be seen with a naked eye, in places where street lights don't wash out the stars. Discovery of Andromeda settled a big debate in astronomy, that Milky Way in not all of universe, but that there are other "island universes" out there.
The disk of the galaxy is 260,000 light-years across, 2.6 times larger than that of Milky Way. The galaxy contains about 1 trillion stars, while the Milky Way has about 200 billion. The stars are crammed into the galaxies core so much that its center blazes with bright starlight. In the pink and blue images, galaxy's star dust is represented in pink, and swirls around blue stars.
Andromeda has a smaller companion galaxy close by, labeled as M32.
Andromeda is expected to collide with our galaxy in about 4.5 billion years. But I wouldn't worry about that. I would worry about making sure you are part of God's kingdom at that time, with a job to do in managing the future universe.
Sources:
http://nasaimages.org/luna/servlet/detail/nasaNAS~12~12~64342~168847?qvq=q:andromeda+galaxy