error: action 'index' could not be found for Userscontroller

When I go to my localhost:3000/users page, I get:

Unknown action
The action 'index' could not be found for UsersController

What does this mean? That I need to define "index" in my controller?

Yes, you have to create the action "index" in your controller (Users)

def index
end

And then, need to create respective view for it.

When I go to my localhost:3000/users page, I get:

Unknown action

The action ‘index’ could not be found for UsersController

What does this mean? That I need to define “index” in my controller?

yup. define the action or just create an index.html.erb template in app/views/users.