What does rubyinstaller install?

The rubyinstaller (downloaded from https://rubyinstaller.org) installs basically 4 things on your PC:-

1. ruby (use ruby -v to check)
2. gem (use gem -v to check)
3. bundler (use bundler -v to check)
4. rails (use rails -v to check)

This is as of 19-Feb-2023 and do not confuse rubyinstaller with railsinstaller.