Is there a difference between `factory_girl` and `factory_girl_rails` Ruby Gems? I have a recurring problem with an error in RSpec Testing: "uninitialized constant FactoryGirl (NameError)".

Somebody told me that there is a difference between the two (this is really confusing) and one needs the other to work or something along those lines?

My spec\_helper file has both:

```
require 'factory_girl'
require 'factory_girl_rails'

```

My Gemfile has:

```
gem 'factory_girl_rails'

```

Here is the full error:

```
uninitialized constant FactoryGirl (NameError)
    from /srv/homes/rvm/gems/ruby-2.0.0-p247@global/gems/rspec-core-2.14.7/lib/rspec/core/configuration.rb:896:in `load'
    from /srv/homes/rvm/gems/ruby-2.0.0-p247@global/gems/rspec-core-2.14.7/lib/rspec/core/configuration.rb:896:in `block in load_spec_files'
    from /srv/homes/rvm/gems/ruby-2.0.0-p247@global/gems/rspec-core-2.14.7/lib/rspec/core/configuration.rb:896:in `each'
    from /srv/homes/rvm/gems/ruby-2.0.0-p247@global/gems/rspec-core-2.14.7/lib/rspec/core/configuration.rb:896:in `load_spec_files'
    from /srv/homes/rvm/gems/ruby-2.0.0-p247@global/gems/rspec-core-2.14.7/lib/rspec/core/command_line.rb:22:in `run'
    from /srv/homes/rvm/gems/ruby-2.0.0-p247@global/gems/rspec-core-2.14.7/lib/rspec/core/runner.rb:80:in `run'
    from /srv/homes/rvm/gems/ruby-2.0.0-p247@global/gems/rspec-core-2.14.7/lib/rspec/core/runner.rb:17:in `block in autorun'
****@epi-stu-hut-shell3:~/projects/project4/spec/factories$ 

```