Why are some stars bright and other dim?

Question: Why are some stars bright and other dim?
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Asked by anon-335301 on 5 Oct 2022.
- Jack Reid answered on 5 Oct 2022:
  
  Different stars are often of different types. Some, like our Sun (G-type), are medium-sized and yellow. Others are much larger and strongly red. Some are small, and blue-ish. As well as different sizes, they are at different distances. Proxima centauri is the nearest to the Sun, and some are billions of light years away. As a result, some seem brighter, and others dimmer.

Question: Why are some stars bright and other dim?