How to implement same routes pattern for different models in Ruby on Rails?

You didn't gave details about your code, so I'm going to write a generic answer. You can adjust to your code.

In most cases we have few static pages, like about, home and maybe something more

So, based on that, you can make specific routes for these static pages, and another route to categories.

get '/home'      => 'static#action'
get '/about'     => 'static#anotheraction'
get '/:category' => 'categories#action'

You can rename routes as the following:

get 'categories', path_names: { index: 'category' }
get 'pages', path_names: { index: 'page' }

See this link Override some routes

If you want change all routes that called categories to category Try it:

get 'categories', :path => 'category'

See this link Change all resources that called 'categories'

For /science to be show category that is name "science" Try this:

1. change routes as:

   get 'categories/:name' => 'categories#show'

2. In action show in categories_controller read category using @category = Category.find_by_name(params[:name])

You can add remaining routes as the following using index_controller:

get '/home' => 'index#action'
get '/about' => 'index#anotheraction'

To change your URL between two controllers Try This:

1. In pages_controller in action show do this: if Page.where(name: params[:name]).first.present? your code to show this page else render 'categories/show' end

2. Check this link render to another controller whit another action