Drush make file is a plain-text file, which describes the components of a drupal installation. Drush can use it to create ready-to-use drupal sites, pulling sources from various locations. It does this by parsing a makefile and downloading the sources it describes. In practical terms, this means that it is possible to distribute a complicated Drupal distribution as a single text file.
- Select the version of drupal you want to install
- Select the modules you want
- Select the libaries you want to use