How to search in rails from two models?

I'm developing a Ruby on Rails web application that consists of two registrations, either as a publisher or an advertiser. How many models would I need? Just a User model or more?

• If there are two specific registration forms where one can either be a publisher or advertiser. Would both still fall under the user model or have two user models that reflect both?

• Answer:

  One is enough unless you have different properties for each type of user. By the way, StackExchange is probably a better place for specific coding help than Quora.