From Drupal Association
From Los Angeles Drupal
From Drupal 4 Gov
From WebWash
Drupal is the less popular is more difficult but has the best reputation, the below are it is main characteristics to learn it demands more time and effort, but if you love it to do it. If not it is ok. In the article, I include the 19 main characteristics of Drupal, of course, it has more elements but you can read articles, see videos buy books, and course. If you want to learn about Drupal and its man characteristics you must read and play with it.
--- little difficult
--- less popular (3,4 % CMS market)
--- Free
--- most secure
more main characteristics are:
--- Includes Cache functionality
-- includes post types
---includes forum
--- proper for big scale projects
more characteristics of Drupal are:
--- written in PHP, HTML, CSS, JS
--- templates using Bootstrap
--- it has less of free Plugins & Templates
--- it is using for every theme part a copy of the base theme file with the new modifications
–- it uses SEO URLs
–- it is light (faster)
more characteristics of Drupal are:
-– it includes SEO functionality , Optimization & Security to edit .htaccess
--- less community support (since is less popular)
-- Mobile-friendly (characteristic of Drupal)
-- Blogging
-- Ecommerce