What is the use of freezing gems in Ruby on Rails?

When you freeze the gem, it copies it to the / vendor directory in your app, and the app downloads it before it loads the version of the gem installed in the normal rubygems path.

The advantage is that this means that when you add the source code of an application to another computer, you have the gem already available for the application without having to install it separately on the machine, and you also know that the version of the gem is on which you trust is available. One of the drawbacks to this approach is that you cannot do this for gems that have C components that need to be compiled on installation.

There are currently other mechanisms to help manage the installation of the gems that your application depends on, such as geminstaller , that can be used to semi-automate the installation of the gems your ad relies on.