There’s a wealth of information out there, http://ruby-doc.org/core-2.3.0/Hash.html for example is pretty clear on what hashes are.
You need to get your head around some of the basics, there are plenty of tutorials out there, https://www.railstutorial.org/ is one that comes up often, http://guides.rubyonrails.org/getting_started.html is the most obvious place to start.
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solved hashes — Seem like mutant potatoes [closed]