What is the difference between rails and rake?

Question

What is the difference between commands rake and rails in Ruby?

Which one is faster and why?

Answer 1

rake is a Make-like program implemented in Ruby.

rails is a web framework, which also has some rake tasks.

This means that you can have a ruby program with rake but without rails, but not the other way around.

By itself, rake will be faster because you don't need to load the whole rails application.

But when launching a rake task, it can have dependencies, for example the :environment dependency in a rails app, which tells rake to load the rails environment and quite a bit of your application depending on the current environment.

In this case, the initialization of a rake task may take as long as a rails command.

Please note that the actual task run needs also to be taken into account, it can be very short or take several minutes.

For example, rake db:migrate, which is a rails task available by default, runs the migrations on the database, which can be time-consuming if the database is already populated and/or you have a lot of migrations