Currently I am using wordpress as a CMS system, Now I am planning to move towards Drupal, I need to know the major differences between both.

Drupal is more powerful anf has great features built in the core which eliminates development time.

Rich admin interface than wordpress.

Module dependancy using observer design pattern.

More scalable than wordpress and have templating system.

Drupal has a learning curve than wordpress 

Drupal is better in secuirty matters othwise both platforms are equal for CMS purpose

Wordpress is used more for a blog website 

Drupal is more powerful to create a complex website and yo u can override it functionality easly  by using theming method and templates 

You can also have a look on joomla , pyro cms 

Drupal is more of a web application development platform (CMS) But wordpress  is  blog  not CMS  Every time need  plugins to feel as CMS