Galaxies: enormous star communities
Galaxies contain many individual planetary systems and can also contain dark matter, stellar remnants, and star-forming clouds. They are not single giant stars.
A galaxy’s appearance depends on its structure and our viewing direction. An edge-on spiral may look like a thin streak. Shape is evidence to investigate, not a complete account of a galaxy’s history.
Wonder about this
Could a galaxy contain many solar systems?
A science clue
Yes. It can contain enormous numbers of stars and their planetary systems.